SEARCH RESULT

In recent years, significant progress has been performed in designing and producing polymer/ceramic based 3D porous scaffolds for tissue engineering applications. Conventional metals used in hard tissue applications currently are unsatisfactory due to density and mechanical mismatch between the implant and the hard tissues. Therefore, implant materials with higher mechanical strength than bone result in stress shielding. Moreover, some components of these materials might be toxic under in-vivo conditions. Polymer/nano-hydroxyapatite composites are currently investigated to solve the problems arising from the conventionally used biometals. This study investigates the contribution of pore parameters (Total porosity, pore size, pore distribution, pore morphology) on various characteristics of scaffolds for hard tissue applications.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Zafer Evis

In this work, polypropylene/thermoplastic polyurethane (PP/TPU) blends of different weight ratios (75/25 and 25/75) were processed by melt blending using a maleic anhydride-grafted polypropylene (PP-g-MA) copolymer as coupling agent. The influence of the amount of the coupling agent (5-11 phr), TPU concentration (25-75 %), normal load (2-4 N) and sliding velocity (60-72 rpm) on the wear properties of the blends were characterized through pin-on-disc abrasive wear test. A 24 full-factorial experimental design was conducted to screen the significant factors influencing the wear resistance of the blends. Additionally, tensile, flexural (three-point bending) and dynamic mechanical analysis (DMA) tests were performed for determining the mechanical properties of the blends. According to the results, the factors that have the greatest effect on the wear rate are as follows: Normal load, TPU concentration, sliding velocity and PP-g-MA concentration, respectively. The wear rate of the blends increases by increasing the normal load, TPU concentration, sliding speed, and slightly decreases by increasing the PP-g-MA concentration. As expected, the mechanical results also showed the apparent superiority of the PP75/TPU25 blends over the PP25/TPU75 blends, because of the higher content of rigid segments in the blends. In the case of PP g-MA, different results were obtained with the concentration.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

S. Savas

In this research, adhesive wear behavior of FeCr slag coating in water environment was investigated. FeCr slag coatings, deposited onto AISI 420 stainless steel specimens with atmospheric plasma spray (APS) method, were subjected to adhesive wear tests in aqueous environment using a pin-on-disk tribometer. 7N load, 0,08 m/s sliding speed and 538 m sliding distance were used as sliding wear test parameters. In addition to the SEM analyses of the worn samples, friction coefficient graphs and 3D profilometer measurements were used to evaluate the wear performance of FeCr slag coatings in water environment. Surface wear micrographs of the FeCr slag coating worn under aqueous conditions indicate that, friction induced tribological layer formation is reduced as compared to dry sliding wear test results, and resulting surface cracks led to local spallations. Also, friction coefficient under aqueous conditions was found to be three times lower than the average friction coefficient obtained under dry conditions.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Y. Kucuk Mustafa Sabri Gök Mecit Oge

The purpose of this study is to examine the use of TWIP and TRIP steels in clutches, which has begun to be demanded in the automotive sector in recent years as an alternative to industrial steels commonly used in dry clutches, and to compare the formability ability and stiffness at various thickness. Since the cover formability and stiffness have high effects on functioning of clutch, it needs to be well optimized according to the operating conditions. TWIP and TRIP steels are a member of advanced high strength steels (AHHS) which are highly preferred steels for their reduction in strength and elongation ratios. They have many advantages such as CO2 emission reduction, energy saving, cost saving. In this article, the formability of DD14 (mild steel), TRIP and TWIP steels in the clutch cover was investigated by comparative stamping simulation analysis at various thickness. In addition, the stiffness behaviors of the DD14 and TWIP980 steels of the clutch cover were investigated at defined thickness by comparative FEA analysis. The results obtained from analysis will be used for modelling of cover made of AHHS under operational conditions.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Mehmet Onur Genc Ahmet Koray Pehlivan

Using sheet laminated die is a suitable option to decrease the manufacturing costs and design time for prototype manufacturing. The surface geometries of the dies are obtained from sheet metals which were cut by laser cutting machine. To obtain proper geometries from laser cut, side views of the sheets are necessary. This process is named as nesting operation. This operation is the most time-consuming process of this method. In this study nesting operation was obtained from newly developed computer code in the MATLAB® software. Input file of the solid model is imported to the MATLAB® software, which provides the slicing geometry into desired parts or lengths. On the other hand, to decrease the manufacturing costs modular die sets are developed. Modular dies allow using different laminated dies in one set up. Aluminium sheets are used as a sample material in deep drawing operation. This study presents an alternative prototyping method by increasing the efficiency of sheet laminated die technology.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Yigit Ugurlu Hakan Kalkan Besim Baranoglu Serpil Erdonmez Ismail Durgun

Over the last decade different kinds of industrial wastes have been successfully employed as fillers in polymer composites for use in various fields. The aim of this experimental work is to evaluate the possibility for the utilization of fly ash obtained from iron and steel industry for use in polyester composites. With this aim neat polyester samples were cast in Teflon mold as control samples. Then fly ash was added to polyester matrix 10%, 20% and 30% by weight ratios. In addition, 9% fly ash+1% TiO2, 18% fly ash+2% TiO2, and 27% fly ash+3% TiO2 hybrid series were prepared to see the effect of TiO2 powders. Impact and tensile tests were conducted on the prepared samples. The results showed that the maximum impact strength was obtained from the composite samples having 20% fly ash. The increase in the impact strength was threefold compared to the neat resin. Having a hybrid structure with the addition of TiO2 caused a reduction in the impact strength compared to the only fly ash added samples with the same ratio. Elasticity modulus increased with the addition of only fly ash and hybrid additions whereas elongation to break and breaking strength decreased.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Halil DEMİRER Yalcin BOZTOPRAK

Friction stir welding (FSW) is a relatively new solid-state joining method which utilizes the action of a rotating tool to heat, plasticize and forge the material in the weld zone to produce coalescence between the two parts to be joined. FSW does not require an external heating source, shielding gas or filler material. Therefore it is more energy efficient and environmentally friendly than fusion welding. It is also a simple process and can be easily automated. When utilized under proper conditions, FSW produces eventually defect-free uniform welds that are superior to fusion welds. FSW is now extensively employed in joining aluminum alloys for aerospace, automotive, ship buildingand chemical industries. In addition, recent developments of the process and tools allowed welding of high strength materials such chromium alloy steel and titanium alloys, and the welding of dissimilar metals such as magnesium to aluminum, titanium to aluminum and steel to aluminum. The technology is also being explored for the similar and dissimilar welding of polymers and polymer composites.State-of-the-art friction stir welding will continue to be a critical technology as we continue to learn more about the process physics and material interactions.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Jamal Sheikh-Ahmad

Nano hydroxyapatite doped with different fractions of zinc (0-0.5 mole%), silver (0-0.5 mole%), magnesium (0-0.5 mole%) and sulphate (0-0.5 mole%) ions has been synthesized successfully and rapidly through microwave irradiation technique. The impact of dopants on the phase formation and microstructure of the powders were investigated using X-ray diffraction (XRD) technique. XRD analysis showed that with an incorporation of Zn2+, Ag+, Mg2+and SO42- ions into HA structure resulted in peak broadening and reduced peak height due to the amorphous nature and reduced crystallinity of the resulting HA powder. The in vitro bioactivity of all materials was evaluated by immersing the samples in the Simulated Body Fluid (SBF) over 14 days at 37 °C. FESEM and EDX analysis confirmed the formation of bonelike apatite with Ca/P ratio between 1.3-1.8 on the surface of the samples. FESEM images suggest that incorporation of multi-ions into the structure increased the surface reactivity of the samples and, as a result, a higher degree of apatite growth was observed for all doped samples. The materials obtained can be considered a promising material for coating of orthopedic and dental implants in surgical applications.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Ammar Z. Alshemary Zafer Evis

Titanium alloys are used in many specific applicants such as biomedical, military, sporting goods and aerospace industry due to their high strength properties and low aspect ratio. Even though their outstanding properties, titanium alloys have low utilization rate and relatively low recycling ratio during manufacturing of Titanium parts. In order to determine its mechanical and impact properties for low-cost Ti-based alloy applications, powder size distribution and compacting pressure strongly affect the microstructural properties of the sintered Ti6Al-4V alloy. This paper presents how the narrow particle size distribution affect the impact properties of both recycled and commercially available Ti-6Al-4V alloys. Below 40µm particle size distribution range of Ti-6Al-4V alloys were conducted on 3point bending, Charpy impact test and microstructural evaluation. Results indicate that -40µm size distributed and recycled Ti-6Al-4V alloys show more brittle behaviour than commercial available alloys.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Mustafa Ustundag Mehmet Fahri Saraç Remzi Varol

In this work, Brinell hardness test, impact test, bend test results of four different types of honeycomb composite materials, which are important for todays in the Civil Aviation Sector and which have been undergoing significant improvements over the past 20 years, have been investigated. The thickness of the mechanical properties of the composites differed with the length of the part and the chemical resin used. The white material in 1,2 cm thickness is used in side and ceiling in cargo area. The light yellow materials is 1,2 cm thickness and is used on the cargo floor and on the wet and dry floors of Airbus, Boeing branded aircraft. Black materials (on wet floors) material in 9,9 cm thickness and used in Passenger Glasses. Yellow Color resinized honeycomb composite in lyophilized form is 1cm thick and used on the bottom of cargo section. Hardness measurements were carried out with a 2.5 mm ball and a load of 187.5 kg under the Brinell Hardness Tester . When the hardness results were examined, when the white composite was damaged, the highest hardness value was found as yellow composite (54,92 HB) value of black composite (26.02 HB). The open saddle stiffness is 31,43 HB.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Muharrem Ilbeyi Incedere Emre Yildirim Emre Demirci Batuhan Ozusta Hayrettin AHLATCI Yavuz Sun Yunus Türen SAİT ÖZÇELİK Fazil Hüsem

The influence of microwave absorbing properties of polyvinyl butiral (PVB)/BaTiO3 composites were investigated in the 1-14 GHz. PVB/filler particles (BaTiO3) composites were prepared with 85/15, 90/10 and 95/5 mixture ratios via Ultrasonic Probe Sonicator method in solution. The complex permittivity (ε’- jε’’) and permeability (μ’- jμ’’) of the composites have been measured at different microwave frequencies in 1–14 GHz employing vector network analyzer (Keysight N9926A). The reflection loss (RL) of composites was calculated and evaluated using the theory of the absorbing wall. The results show that absorption is increasing as the fillers rate increase and thickness is decreased. This can be understood based on quarter wave principle within the frequency range from 1 GHz-14 GHz for different thickness.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Yuksel Akinay Fatih HAYAT Hasan GÖKKAYA

Boric acid (H3BO3), also named as orthoboric acid, boracic acid, hydrogen borate, borofax and acidum boricum, are widely used in mild antiseptic and antifungal applications, especially as eye and ear drops in pharmacy. In this study, the optimized structure, energy values, vibrational wavenumbers, NMR isotropic chemical shifts and the conformations of boric acid molecule were theoretically obtained with density functional theory (DFT). The molecular structure was confirmed by nuclear magnetic resonance and FT-IR experiments and compared with literature studies.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Tuba Ozdemir

In this study, the AIR-X 400-W wind turbine is modeled. The solid model of turbine components were generated by using ANSYS 13.0 software. Contrary to materials used in classical turbines, shape-memory alloys were preferred at blade root connections and rotor hub. Structural analyzes confirmed that the weak regions are screw connection points. In the created scenarios for turbine we obtained that turbine was more durable and has longer life than the 4140 structural steel when Ni-Ti was used in blade root connection and Cu-Zn-Al was used in rotor hub. Also Ni-Ti and Cu-Zn-Al combination was determined as approximately 2.1556 times longer life than 4140 structural steel.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Cem Emeksiz Numan Sabit Cetin Mumin Kucuk

AlSi12 alloys and alloys produced by Mg addition at different ratios (1% - 2% and 4%) were manufactured by pressurized casting method. Quartz tubes with an inner diameter of 8 mm were used in the castings of the alloys. All castings were carried out in an argon gas atmosphere. These samples (7 mm x 20 mm) were homogenized at 520 ° C for 6 hours. Samples prepared by standard metallographic procedures were immersed in a jar containing 30 gr/l NaCl + 10 ml/l HCl acid solution and samples were weighed at 2-6-12-24 hours intervals. It is clear that the increased Mg ratio reduces the corrosion resistance of the alloys. The reason for this decrease in corrosion resistance is Mg2Si which is likely to occur after Mg addition. Intermetallic are thought to accelerate corrosion by forming a galvanic couple with the matrix. As a result of the corrosion test, SEM images taken from the surface also support our corrosion graph. Thus, when we look at the samples without Mg addition, it is seen that the surface deformation is very small compared to the samples produced by Mg addition.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Engin ÇEVİK S. Yasin Harun ÇUĞ Necmi Ozdemir R. Yildiz S. Akka

The milling of carbon fiber reinforced polymers (CFRP) is a challenging process due to the non-homogeneous, anisotropic structure and extreme hardness of this type of material. Tool wear occurring during the machining process and the resulting failure mechanisms including delamination, matrix and fiber breakage have severely adverse effects on surface quality of machined products. Since deterioration of machined surface quality may impair the strength of components, particular importance is attached to this situation especially in aviation industry. As a failure mechanism arising from the machining of the materials, this situation may result in timeless damages on critical components, such that, almost 60 % milled CFRP components are discarded due to delamination-related damages. In this context, investigation of the failure mechanisms resulting from delamination and delamination-related situations arising during the milling of CFRP composites was aimed in the present research.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Dervis Ozkan Mustafa Sabri Gök Hasan GÖKKAYA Abdullah Cahit KARAOGLANLI

The effects of cutting parameters which are used in CO2 laser machines on surface roughness of AISI 304 quality stainless steel sheet after cutting process is examined in this study. 3 mm AISI 304 quality stainless steel is prepared with the help of a determined geometrical model by cutting. In processing experiments, parameters are divided into two sections as constants and variables. Frequency, Duty, Nozzle, Material, Speed and Lens parameters are kept as constant, Power, Focus, Pressure and Substitute Gas parameters are kept as variable. The experiments were carried out in accordance with the full factorial experiment. The average surface roughness values was measured after cutting experiments and evaluated by ANOVA (Analysis Of Variance) variance analysis. The measured average surface roughness values ranged from 1.261 to 4.156 µm. The parameters of power, pressure and auxiliary gas are affected by surface roughness, Focus distance has not been effective. This study is thought to have an important position to light the way for the companies which take place in production sector.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Murat Tunc Gökhan Sur Hasan GÖKKAYA Muammer Nalbant

In this study, it was aimed to put together hydrophobic iron oxide particles and hydrophobic PVDF (polyvinylidene fluoride) polymer on a glass surface as a coating to obtain a superhydropobic surfaceand investigate the anti-icing properties of that superhydropobic surface. Submicron size hematite particles, αFe2O3 which had flowerlike morphology was produced by using iron nitrate which was a cheap resources of iron oxide. Polyvinylidene fluoride (PVDF) polymer which was ready-made was completely solved in dimethyl formamide (DMF) and tetrahydrofuran (THF) solvents. Then hematite particles and solubilized PVDF polymer were mixed at a ratio of ????:???? and this mixture was then applied to the glass surfaces as a coating by using dip coater and spin coater, individually. The water contact angle of glasses coated by solution that was obtained by combining iron oxide particles and PVDF was measured to be 158±5. In this study, PVDF polymer provided the low surface energy condition and the flowerlike morphology of iron oxide particles provided the nano scale surface roughness condition. When these conditions were met, the anti-icing behavior of that surface was examined. Even the coated glasses were iced, in 3 seconds the ice was removed from the surface by air stream.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

N. Basaran A. Capoglu

In this study, the drillability of Al/15B4C metal-matrix composites with untreated, cryogenically treated and cryogenically treated+tempered HSS twist drills has been evaluated with respect to tool life, tool wear and surface roughness. The machinability tests were performed with untreated (U), cryogenically treated (CT) and cryogenically treated and tempered (CTT) tools at three different cutting speeds (Vc:17, 21 and 26 m/min), at three different feed rate (f:0.06, 0.08 and 0.1 mm/rev) and under dry drilling conditions. First, following the applied cryogenic treatment, the change in the microstructures of the cutting tools was evaluated with scanning electron microscope (SEM) images taken from different points of each sample. At the second phase, the chip volume removed from the workpiece material was determined until the drilling ability of the tools came to an end. SEM images were taken in order to examine and determine the wear mechanisms and wear types emerged on the cutting edges as a result of the drilling tests. Finally, surface roughness of the hole walls were measured and the effects of drilling parameters and cryogenic treatment applied on the cutting tools were evaluated. In drilling of the Al/15B4C reinforced composites, the cryogenically treated (CT) and cryogenically treated+tempered (CTT) tools showed 50% improvement in tool life when compared to the untreated (CHT) tools. Outer corner and flank wear types were observed on the cutting tools after the drilling of Al/15B4C reinforced composite. While the cryogenically treated (CT) tools improved the surface roughness of the holes by approximately 1%, cryogenically treated+tempered (CTT) tools improved by approximately 10%.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Ali Riza Motorcu Ergun Ekici

In this study, the effect of homogenization heat treatment on the corrosion behaviour and mechanical properties of Co-Cr (Dental), Co-Cr (Denture) and Ni-Cr (Dental) based casting materials used as dental implant materials was investigated. Samples prepared as 7 mm in diameter x 10 mm cylindrical in a special silicon-graphite-containing powder mixture for preventing oxidation were annealed at different times in the range from 0.5 to 3 hours at 1000 ° C. Microstructural investigations of the samples heat treated and casted was performed on longitudinal and circular sections by Leica DM ILM model optical light microscope and then hardness measurements were carried out with Brinell hardness tester with 2,5 mm ball and 187,5 kg load. The corrosion behaviour of the Co-Cr and Ni-Cr based materials formed in the optimum parameters, which show improvement in the final mechanical properties of microstructure and hardness measurement data, compared with cast materials, was studied by potentiodynamic polarization test in Hanks liquid. The corrosion damage mechanism was determined by scanning electron microscopy. The icorr and Ecorr values of the heat-treated materials evaluated after the corrosion made by the potentiodynamic polarization test method has been increased with respect to that of the casted materials.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Medine Kilinc Batuhan Ozusta Gulheser Dogancik Canan Dursun Hayrettin AHLATCI Yunus Türen Yavuz Sun Alperen R.B. ÖZSARI

The effect of microcapsulated red phosphorus (mRP) was studied on the flame retardant, thermal and mechanical properties of thermoplastic polyurethane (TPU) composites containing Huntite& hydromagnesite (HH). The flame retardant properties of TPU based composites were investigated using limiting oxygen index (LOI), vertical burning test (UL 94), thermogravimetric analysis (TGA) and mass loss calorimeter. The mechanical properties of composites were studied using tensile test and dynamic mechanical analysis (DMA). According to the test results, the adjuvant effect of mRP was observed in terms of both flammability and mechanical properties of composites. The highest LOI value (32.5), the highest UL-94 rating (V0) and the lowest pHRR (155 kW/m2) value were observed with the partial substitution of 7 wt% mRP with HH. The tensile strength also increased at about 60% with respect to TPU/50HH. The mRP showed the synergistic effect by increasing the barrier effect of residue in the condensed phase and the formation of active radicals in the gas phase. The mRP showed adjuvant effect on mechanical properties due to the plasticizing and compatibilizer effect of low molecular weight epoxy resin carrier.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

L. Atabek Savas Umit Tayfun Mehmet Dogan

In this study, a comparative examination of the effect of sliding speed, as a ball-on-disc sliding wear test parameter, was investigated under aqueous conditions. For this purpose, AISI 420 stainless steel specimens were prepared in cylindrical form (Ø25x8 mm), then they were coated with commercially available ceramic coatings (Cr2O3 and Al2O3) using APS technique. Adhesive wear tests were carried out by the use of a ball-on-disc testing rig. The tests were performed under 7N load, 0.08 m/s and 0.12 m/s sliding speeds. After the wear tests, worn samples were subjected to SEM analysis and profilometer measurements. The effect of sliding speed on wear performance of ceramic coatings was evaluated based on the analysis and measurement results. SEM images of Al2O3 coating indicate that, increasing sliding speed also increased the effect of plastic deformation, further inducing tribological layer formation. SEM images of Cr2O3 coating surface, on the other hand, indicated no significant effect of sliding speed at macro or micro level, which is mainly attributed to the higher hardness of Cr2O3 coating than Al2O3 coating. Friction coefficient graphs of both coatings indicated no significant change at both sliding speeds.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Mustafa Sabri Gök Y. Kucuk Mecit Oge

In this study, effects of aging on the mechanical properties of Al-Si alloy that containing 0.20 wt. % and 0.40 wt. % Mg were investigated. All alloys were homogenized at 550oC for 12 hours. The solution heat treatment of the alloy was carried out at 525oC for 3 hours and then samples were water-quenched. The specimens were artificially aged at 180oC for three different time durations. The structural, morphological and mechanical properties of the specimens were examined by using scanning electron microscope (SEM), X-Ray diffraction (XRD), and compression, notched impact, wear and hardness tests. it was determined that the values of hardness, yield and ultimate strengths increased but the ductility of the alloy decreased with aging time for both alloys. The wear resistance of 0.40 wt. % Mg containing alloy was higher than that of 0.20 wt. % Mg containing alloy. It was observed that increasing Mg ratio resulted in higher hardness, yield and ultimate strengths and impact toughness.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Halil Eren Ali Gungor

In this study, the effect of zirconium on the recrystallization resistance and mechanical properties of an AlMg-Si alloy was investigated. Zr was added in an amount of 0.1% and 0.2% Zr by weight. Alloys produced by vertical direct chill casting method were cold deformed by 70% in thickness. Deformed alloys were annealed at 500 °C for 10 and 30 min., which is close to the preheating temperature used in the extrusion process. Then, the alloys were prepared metallographically and the % -recrystallization volumes were determined by image analysis. The alloys in the form of billets were subjected to the extrusion process in the form of a hollow profile and then the tensile specimens were taken and subjected to tensile tests at room temperature. The fracture surfaces of the tensile specimens were investigated by scanning electron microscope and the fracture mechanisms were investigated depending on the Zr content. Experimental results show that the recrystallization resistance of the alloy was increased even at a high annealing temperature of 500 ° C with the increase of the Zr content. It was also seen that the strength values increased with the increase of Zr ratio in the extruded alloys.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Fulya Kahriman Muzaffer Zeren

Clutch disc is a one of the most important component in powertrain system in charge of the torque transmission by friction. In addition to transmitting engine torque, the clutch disc has the task of preventing torsional engine vibrations from reaching the powertrain. In order to achieve this, the clutch disc is fitted with torsional dampers which are helical compression springs. Another solution instead of helical springs is elastomeric dampers. Recently elastomer materials are widely demanded particularly in automotive industry with the advantages of high damping capability, light weight and low cost. The behavior of these materials under load is not linear and almost incompressible. Due to the increasing interest of clutch modeling, it is important to develop validated models to calculate the static and dynamic stiffness and damping characteristics. In this study, validated hyperelastic finite element model of elastomeric spring was developed. First, hyperelastic material properties of selected rubber material were obtained using physical test. Material model parameters were defined using test data and static simulations of elastomeric spring using finite element analysis were conducted. FEA model was validated with the test results and this model can be used for further clutch simulations.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Mehmet Onur Genc Suleyman Konakci Necmettin Kaya

Today, the world is fighting with increasing air pollution. Air pollution affects human health negatively. Among the factors that increase air pollution, we can add the increasing number of vehicles to meet the needs of the increasing world population. In order to reduce air pollution and health problems associated with increased number of vehicles, lawmakers have introduced some rules for limiting air pollution caused by vehicle manufacturers. These rules are tightened over the years. For this reason, vehicle manufacturers are using new technologies in their vehicles to reduce the harmful gases. The most advanced and most efficient technology used to reduce harmful emissions to the environment in diesel-powered vehicles is selective catalytic reduction (SCR). By using this method, the harmful nitrogen oxides formed in the combustion chamber are reacted with a liquid in a catalyst added to the vehicle to release nitrogen and water vapor. In this work, from past to now diesel fuel emission reduction strategies and the working principles of the selective catalytic reduction system are examined.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Tolga Terzioglu

Titanium and its alloys are commonly preferred implant materials for hard tissue applications. Today more than 4.4 million people have an internal fixation device and over 1.3 million people possess an artificial joint. Not only is there high demand for orthopedic surgeries for new patients every year, but there is also an even higher demand for patients who must receive revision surgeries. In order to enhance the properties of titanium based implant materials, different pretreatment and coating techniques are commonly used. Calcium-phosphate coatings are the most favorable method to upgrade the osteointegration properties of biomaterials. Porous structure of hydroxyapatite enables osteoblast attachment, proliferation and finally leads to osteointegration of the implant material. Biological performance of the coated implant can be improved by substitution of various ions. The goal of this study is to reduce implant rejection caused by the human body and increase the implants lifetime as this new generation orthopedic implants are produced. Mimicking the bone structure by coating metallic scaffold with co-doped Hydroxyapatite in effective way enable strong bone-implant integration. The aim is to prepare a new generation of coating on Ti6Al4V implant. Coated plates were evaluated in terms of their mechanical properties.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Tugce Hacioglu Zafer Evis Aysen Tezcaner

In this paper, SiC particle reinforced magnesium (Mg) matrix composite material fabrication was realized by using high pressure die casting (HPDC) method. The production of the composite materials was carried out by injecting of AZ91 magnesium alloy into the die casting mold thorough the preheated SiC preform reinforcing element having a porous structure. The abrasion strengths, which are important in terms of the application area of the produced composite materials, are measured by wear test using ball-on-disk method. In addition, the microstructures, characteristic features and wear marks of the composites were examined by scanning electron microscopy.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Ali Serdar Vanlı Bedri Onur Kucukyildirim Anıl Akdoğan

Aluminum matrix composites are widely used in automotive, aviation and aeronautics industry due to their high strength, good stiffness, low density, good thermal and electrical properties. Developments of these composites with unique reinforcements are essential to enhance the composite properties. In recent years, graphene nanoplatelets (GNPs) and its ceramic combinations such as silicon carbide (SiC) and silicon nitride (Si3N4) have been rarely preferred to fabricate high-performance aluminum composites. In this study, binary SiC/graphene and Si3N4/graphene reinforced aluminum composites were fabricated by powder metallurgy method for various reinforcement content. From the results, the hardness of the composites has been increased by graphene and its ceramic combinations. While pure Al and Al-0.15%GNPs composite hardness were reported as nearly 52 and 56 in our previous studies, in this study the highest hardness has been measured as 85.2 HV and 82.01 HV for Al30%SiC-0.5%GNPs and Al-9%Si3N4-0.5%GNPs respectively.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Mevlüt Gürbüz Mahmut Can Senel Erdem Koc

Magnesium and its alloys have been widely used in automobile, aerospace, space, electronics and sports industries due to its light weights and relatively high-strength. However, we need higher mechanical properties in applications. It is known that composites of magnesium and its alloys with fibers or particulate increases the properties. Graphene is the one of this material, and it is preferred in these days because of its superior mechanical, electrical and conductive properties. In this study, graphene reinforced magnesium matrix composites were fabricated with powder metallurgy. Density and hardness of these composites were measured. The crystal structure and microstructure of the composites were observed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). From the results, the density and hardness were increased with graphene addition to magnesium.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Emine Ozlem Dengiz Mevlüt Gürbüz

In this study, 1% and 4% pure magnesium were added to pure aluminum alloy by using pressure casting method. These samples (7 mm x 20 mm) were homogenized at 520 ° C for 6 hours. Corrosion tests were performed by suspending samples of certain sizes into 30 gr/l NaCl + 10 ml/l HCl solutions, measuring the mass loss. When we compare the produced alloys, it is observed that as the magnesium addition increases, the weight loss increases and the corrosion resistance decreases. In pure aluminum, 0.84 g/mm2 was achieved at the end of 24 hours, while the weight loss of the samples we added 4% Mg increased by 300% to 2.23 g/ mm2. The decrease in the corrosion resistance is caused by the addition of Mg and the possible formation of intermetallic (Al37Mg3 etc.) in the structure.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Engin ÇEVİK S. Yasin C. T. Kaymaz C. Kayapinar G. Akyuz C. Urhal M. Caliskan M. Kangal

In this present work, the effect of microstructure on the corrosion behavior of magnesium alloys varying with Ca/Al ratio was investigated. Three different alloys with three different Ca/Al ratio 0.58, 0.79, and 0.91 were studied. All three alloys had approximately same Mn content. Microstructure and phase identification of the alloys were carried out by SEM, EDX and XRD analyses. Alloy 1 contains a-Mg, Al2Ca phases and Alloy 2 and Alloy 3 contain Mg2Ca in addition to a-Mg and Al2Ca phases. The amount, size and distribution of secondary phases were strongly dependent on Ca/Al ratio. Although it has been observed that the corrosion current densities of three alloys are very close to each other, alloy 1 had lower value corrosion rate than the other alloys. Thus, it can be said that the alloy 1 is more resistant to corrosion in 3.5% NaCl solution.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Ali Gungor Hamid Ali ELAMAMI Alper Incesu

Carbon fiber reinforced plastic (CFRP) composite materials, among other fiber reinforced materials, exhibit excellent resistance properties against a low specific weight. They have been used in a wide range of contemporary applications particularly in aerospace industry, defense, automotive, machine tools, sports equipment, transportation structures, power generation, oil and gas industry. Various damage mechanisms such as fiber pull-out, fiber break, matrix smearing and delamination damage have been observed in CFRP composite materials in their work. In this study, CFRP composite materials in direction 0º, 45º and 90º were produced by the vacuum bagging method. CFRP composite materials were drilled at different parameters with abrasive water jet (AWJ) machining center. Delamination damage were analyzed.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Meltem Altin Karatas Hasan GÖKKAYA

A composite can be defined as the combination of two or more distinct materials, one of which with superior mechanical properties where a recognizable interface between them to exist. Carbon fiber reinforced resin matrix composites are by far the most commonly applied advanced composites for a number of reasons. However, the main drawback of polymer based carbon fibre composites is the weakness against the impact loads. To solve this problem several methods have been offered so far. Use of delamination promoters is one of the ways of overcoming this deficiency in composite materials. These delamination promoters consist of various inorganic or organic materials which make a greater energy absorption much easier. The effect of delamination promoters on the impact and other mechanical properties of carbon fibre-reinforced plastic has been investigated by many researchers. In this study glass, polypropylene, aramid fabrics and cord fabric were used as delamination promoters in carbon fabric epoxy prepreg composites. Tensile, interlaminar shear strength (ILSS) and drop weight tests were conducted on the composite specimens. The results showed that the specimens having cord fabric layers exhibited less damage on the surfaces. Tensile and ILSS test results also supported this finding.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Halil DEMİRER Yalcin BOZTOPRAK

The use of traditional composites made of polymer composites glass, carbon or aramid fibre reinforced have recently been discussed critically because of increasing environmental consciousness. Natural cellulosic fibre reinforced composites is an emerging alternative to synthetic fibres as a reinforcement in composite materials and polymer based composite materials reinforced with natural cellulosic fibres have received great attention. Today, polymer composites natural fibres reinforced are emerging in the composite applications in a number of fields ranging from automotive to biomedical because they are ecological, their resources are renewable and they are considered neutral toward CO2 emissions. Recently due to increasing interest in eco-friendly materials, studies on eco-friendly fiber obtained from nature have been actively conducted to the area of composite. Although the natural fiber has less strength than the high strength fiber such as the carbon fiber, it has similar strength to glass fiber. Accordingly, it can be applied as very advantageous composite when an appropriate resin has been selected. In this study, the flax/carbon fiber/vinyl ester composite specimens are manufactured and their mechanical properties are evaluated.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Yalcin BOZTOPRAK Halil DEMİRER

The use of traditional composites made of glass, aramid or carbon fibre reinforced plastics have recently been discussed critically because of increasing environmental consciousness. Thus, the recent research and development efforts have led to new products based on natural resources. Furthermore, natural fibre-reinforced polymers made with natural fibres like flax, hemp, kenaf, jute or cotton fibres are important research and development achievements. Flax fibre composites are very competitive with glass fibre composites in terms of stiffness. This is especially the case if the low density of flax fibres (1.4 g/cm3 ) compared to glass (2.5 g/cm3 ) is taken into account. However, Glass fibre reinforced composites, although they have been used very successfully in many applications. In addition to this, glass fibre composites do still have significantly better properties in terms of strength and especially compressive strength. Glass fibres are three dimensional networks of SiO2 whereas natural fibres are highly anisotropic with oriented cellulose microfibrils. The highly anisotropic nature of flax fibres results in failure through micro-buckling. In this study, the flax/glass fiber/vinyl ester composite specimens are manufactured and their mechanical properties are evaluated.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Yalcin BOZTOPRAK Halil DEMİRER

It is called superstructure member rail which is made of cast steel which guides the wheels on the railway vehicles and transverses the forces coming from the axles to sleepers. The fish plate used in joining the rails; cause noise, prevent acceleration, increase repair costs, cause damage in vehicles, cause rail to break etc. it is due to the reasons for the rails welding. Rails usually welded by alumino-thermit rail welding, flash butt welding and electric arc welding methods. Alumino-thermit welding based on the removal of heavy metals by the aluminum of heavy metal oxides. In the flash butt welding method is the rail ends are heated to the melting point with the electrical resistance system without any additional elements then pressure is applied to the molten rail ends so that the rails are welded. In this study, hardness properties, optical and SEM images of alumino-thermit and Flash butt welded S49 rails were investigated. In the optical and SEM microstructure examination, the perlitic structure was generally observed in the source region of the sample to which the burn-in source was applied, while the decarburized regions were observed in the source region of the sample to which the thermit source was applied. Low stiffness values were obtained in the fungus and I profile regions of the rail specimen subjected to the effect of decarburized regions and of the rail specimens subjected to thermit welding compared to the burn-in origin specimen.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Harun ÇUĞ Soner ÇETİN Mustafa DURSUNLAR Hayrettin AHLATCI M. Hüseyin ÇETİN

Present study includes an overview about problems and overcoming methods of micro and nano sized defects came out during production of crystalline silicon (c-Si) substrates for electronic applications. All surface treatment steps such as diamond wire saw (DWS), lapping, polishing, micro and nano sized shaping on surface are performed respectively. Defects occurred during and after the operations and reasons of these were investigated and given via the of scanning electron microscope (SEM), reflectance and roughness measurements. Solutions methods explored and results after application of solution methods were evaluated. Reasonable solutions were discovered in order to overcome the problems behind the production a defect-free Si substrate surface for many electronic applications.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Erhan Kayabasi Savas OZTURK Erdal CELIK Huseyin Kurt

In the present research on milling of carbon fiber reinforced polymer (CFRPs) composites widely used in aviation industry, the effects of different cutting speeds and feed rates on the surface roughness was investigated using tungsten carbidecobalt based (WC-Co) carbide cutting tools. A CFRP composite with 6 mm thickness and 24 layers was used as the work-piece. The tests were performed on a CNC vertical processing center with 100, 200 and 300 m/min cutting speeds, 0.05-0.15 and 0.25 mm/tooth feed rates and 1 mm constant cutting width under dry conditions. Following the tests, the surface roughness of the work-piece was investigated. 5.7 µm surface roughness was obtained with 100 m/min cutting speed and 0.25 mm/tooth feed rate.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Dervis Ozkan Mustafa Sabri Gök Hasan GÖKKAYA Abdullah Cahit KARAOGLANLI

The usage areas of carbon fiber reinforced plastic (CFRP) composite materials are increasing day by day in various industries due to their manufacturability in varying combinations with customized strength properties, also their high fatigue, toughness and high temperature wear and oxidation resistance capabilities render. Some of the damage mechanisms have been observed in CFRP composite materials as well as in other anisotropic and inhomogeneous materials in their work. In this study, CFRP composite materials in direction 0º, 45º and 90º were produced by the vacuum bagging method. CFRP composite materials were drilled at different parameters with abrasive water jet (AWJ) machining center. Surface roughness were analyzed.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Meltem Altin Karatas Hasan GÖKKAYA

Sandwich panels have been widely used in several fields due to their mechanical properties. In this research, the effect of core edge curvature of sandwich panels on their impact performance was examined. In this regard, sandwich panels were modelled for seven different radius of edge curvature (0,5:1:1,5:2:2,5:3:3,5 mm). Al 2024 was used as the face-sheet and core material. Quasi-static impact analysis was carried out using Abaqus finite elements software at 1 m/s test speed and under 8 tons test load. Analysis results revealed that, the use of different edge curvature values affected the mechanical properties such as the amount of absorbed impact energy, maximum peak force and the average crushing force. In conclusion, the amount of absorbed energy increased and the peak force decreased with increasing radius of edge curvature. On the other hand, sandwich panel’s resistance against vertical loads was reduced when the change in curvature resulted in a reduction in the length of the core wall by more than 50%.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

E. ZURNACI Hasan GÖKKAYA

In this study, Vibration Stress Relief (VSR) method which promises to reduce residual stresses in welded parts with applying mechanical vibrations was investigated. Mechanical properties’ differences were compared between vibration stress relief welded parts and non-stress relief welded parts which were S355J2 (St52-3) steel, widely used in the industry. Firstly, tensile tests were carried out and then hardness measurements were accomplished. To investigate the effects of residual stresses on fatigue life, residual stress changes of front and back of the welded plates were measured. Finally, three point fatigue tests were performed to investigate effectiveness of VSR in terms of the fatigue life. It was obtained that tensile strength and fatigue life increased with the decrease of residual stresses after applying the VSR method.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Sinem Kacar Oguzhan Yilmaz

As a protective coating method initially developed for space and aviation industry thermal spray coating techniques have been widely used in several fields. Among a vast number of thermal spray coating techniques, Atmospheric Plasma Spraying (APS) and High Velocity Oxygen Fuel (HVOF) techniques are widely applied against harsh conditions such as wear, oxidation and corrosion due to their high applicability and cost efficiency. In the present research NiCr coating was deposited on Inconel 718 substrate materials using plasma spray and HVOF methods, and the coated specimens were subjected to dry sliding wear tests under 3, 5, 7 and 10N loads at 0,08 m/s sliding speed using a pin-on-disc tribometer. Characterization of the coated specimens was performed before and after the wear tests using conventional characterization techniques. According to the wear loss and coefficient of friction values obtained after the performed tests, the coatings deposited with HVOF technique exhibited a higher wear performance as compared to those deposited with APS technique.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Mecit Oge Fettullah Yildiz S. Parlakyigit Mustafa Sabri Gök Abdullah Cahit KARAOGLANLI

Wear and noise problems in rail systems. Especially in urban inner rails systems are disturbing the environment. In rail systems, many materials are used as brake material. Composite braking materials have been developed to eliminate these adverse effects. In this study, the adhesive wear characteristics of the composite brake material used for braking of railway vehicle tools at different loads were investigated. The tests was carried out on two different braking loads, 15N and 30N, with composite sabo section as abrasive material and as abrasive surface with 220 mesh roughness. The total duration of each test is 15 seconds and the track taken is 10m. The counter-friction material has been renewed for every application. The amount of water added in the aqueous media tests is fixed at 200 ml. At the end of the test, mass losses in aqueous and dry media were investigated. In the conclusion is the following; Mass loss is less in aqueous media. However, similar studies have shown that the productive frictional force decreases, especially at high speeds. Although not very effective in sudden braking, the inefficiency of mass loss caused by friction can be reduced by using the appropriate continuous braking during cruising.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Harun ÇUĞ Orcun Zengin Engin ÇEVİK Hayrettin AHLATCI M. Hüseyin ÇETİN

In this research Al2O3 (Metco 130SF) powder was deposited on AISI 420 stainless streel substrates using Atmosperic Plasma Spray (APS) technique. Wear tests were performed on a ball-on-disc wear testing rig (Turkyus brand) to evaluate the dry and aqueous adhesive wear behaviors of the obtained coatings. Test parameters were specified as 7N load and 0.08 m/s sliding speed. The SEM micrographs of the wear track surface and friction coefficients were used in the analysis of the coating’s wear behavior. Additionally, volumetric mass loss calculations were conducted using a 3D optical profilometer. Friction coefficients were respectively found as 0.7 and 0.35 for dry and aqueous conditions, indicating a nearly 50% reduction in the latter case. The decline in worn volume values was also in proportion with the decline in friction coefficient. The comparison of dry and aqueous environment SEM micrographs show that, tribological layer formation occurred at a reduced level in water, which is attributed to the increase in local heat transfer. Also, surface cracks are more apparent under dry conditions, whereas radial crack formations are observed nearby the edges of the wear track under aqueous conditions.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Y. Kucuk Mustafa Sabri Gök Mecit Oge

Isotope effect in Bi based high temperature superconductors calculated using BCS theory. I was taken into account thickness conducting layer in calculation of Coulomb pseudopotential. Obtaned results in agreement with experimental data.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Iman Askerzade

In this experimental study, holes were drilled from end to end with dry drilling process on the Al/10B4C/5Gr hybrid composite workpiece material at three different cutting speed (Vc=18, 25 and 35 m/min), at three different feed rate (f=0.08, 0.112 and 0.16 mm/rev) and with three different drill point angles (PA=118, 130 and 140) in 5 mm diameter using uncoated carbide drills. Taguchi L27 orthogonal array was used to perform the drilling of hybrid composite. Multi performance optimization of the processing parameters was fulfilled using Gray relational analysis (GRA). Two process performance parameters, that is, surface roughness (Ra) and roundness error (Re) were optimized. The result of this study suggest that drill point angle (33.88%), cutting speed-drill point angle interaction (20.15%) and cutting speed-feed rate interaction (17.22%) have respectively the most significant effect on roundness error and surface roughness of the hole. Optimal levels of drilling parameters in the drilling of Al/10B4C/5Gr hybrid composite were determined as Vc=35 m/min, f=0.160 mm/rev and PA=130 point angle.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Ali Riza Motorcu Ergun Ekici

The present study theoretically investigates for the localized collective excitations in the antiferromagnetic superstructures which appear inside forbidden gaps. Solving full Maxwell’s equations with electromagnetic boundary conditions and using the effective- medium theory, we derive the dispersion relation for localized excitation (surface-guided) modes for two antiferromagnetic superstrutures : a) Junction antiferromagnetic superlattice and antiferromagnet;a nd b) Junction of two antiferromagnetic superlattices coupled by the antiferromagnetic film in the presence of external magnetic field. Numerical applications are made to various antiferromagnetic systems and then are discussed in detail. The results obtained in this study can be utilized to design waveguide devises.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

R.T. Tagiyeva Askerbeyli

Drilling operation is required for assembly of carbon fiber reinforced polymer (CFRP) composites. Surface roughness, hole entry delamination and hole exit uncut fibers occurred during drilling are important factors affecting the properties of the drilled holes. In this study, the drilling parameters for the minimum surface roughness (Ra), delamination factor (Df) and uncut fibers factor (UCFF) were optimized for drilling of CFRP composites with uncoated and TiN coated solid carbide drills. Machinability experiments were carried out in Taguchi Method L18 orthogonal array experimentation. Firstly, the % effects of cutting tool type (uncoated, TiN coated) and drilling parameters (cutting speed, feed rate) on Ra, Df and UCFF were determined via Variance Analysis. In the second stage, the drilling parameters for minimum Ra, Df and UCFF are optimized using Gray Relational Analysis (GRA). TiN-coated tools provided lower Df and UCFF values while better Ra was achieved with uncoated tools. No significant effect of cutting tool type on Ra, Df and UCFF was observed. The most effective parameter on Ra was the cutting speed, whereas the most effective parameter on Df and UCFF was feed rate. As a result of the GRA, minimum Ra, Df and UCFF values were achieved with TiN coated drills at V:45 m/min cutting speed and f:0.04 mm/rev feed rate.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Ergun Ekici Ali Riza Motorcu

In this study, porous pumice powder containing polypropylene (PP) composites were prepared. Acidic pumice (AP) and basic pumice (BP) were modified by using silane coupling agent before addition to PP matrix. Additionally, pumice filled maleic anhydride grafted polypropylene (Ma-g-PP) composites were prepared. Melt-blending (extrusion) which is a common industrial technique was used for the preparation of the polypropylene/pumice composites. After the extrusion process, granulized form of the composites were injection molded for the preparation of test samples. In addition to mechanical characterization of prepared composites, water absorption test was applied to PP and composites in order to examine their possible outdoor applications. Tensile test, dynamic mechanical analysis (DMA), melt flow index tests and scanning electron microscopy (SEM) were also performed. PP composites containing silanized pumice and Ma-g-PP based composites showed better mechanical properties. These results were also confirmed by the SEM micrographs. According to SEM analysis, silanized pumice particles exhibited homogeneous dispersion inside the PP matrix due to the better surface compatibility between pumice and PP. No remarkable changes were observed for melt flow values of especially acidic pumice containing composites compared with PP.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Yasin Kanbur Umit Tayfun

The ordered mesoporous carbons (OMC) have attracted considerable attention in the field of fuel cell research. In this study, OMC supported Pt catalysts were prepared by different loading strategies. An OMC carbon with 8.1 nm mean pore size and 711 m2/gr surface area was synthesized using an organic-inorganic triconstituent self-assembly method. Then, OMC supported Pt catalysts were prepared by three different strategies; in-situ synthesis (Pt/OMC-I), wet impregnation (Pt/OMC-W) and wet impregnation preceded by surface modification with HNO3 (Pt/OMC-M). Nitrogen adsorption analysis gave surface areas ranging between 454 and 685 m2/g. The mean pore sizes of Pt/OMC-W and Pt/OMC-M slightly increased due to the considerable loss of micropore volume after the metal loading. TEM images of the catalysts showed that the Pt/OMC-W and Pt/OMC-M catalysts exhibited uniform particle distributions. Performance tests were carried out in a PEM test station, using the membrane electrode assemblies prepared by the OMC supported catalysts. Pt/OMC-M gave the best performance with a maximum of 73 mW/cm2 at 200-220 mA/cm2. The results showed that surface modification led to improved performance and Pt/OMC-M can be safely used in place of Pt/C.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

S. Gunes C. Guldur

In this study, vacuum-gas infiltration setup was used to produce aluminium-B4C composite foam. The mentioned method involves addition of space holder materials and a dissolution technique to remove them after solidification of the metal. As space holder materials NaCl particles were selected and mixed with B4C powders to produce A360 (AlSi10Mg) aluminium-B4C composite foam. By changing the weight ratio of B4C particles, the alteration of the properties such as compression strength, density and porosity were investigated. Additionally, computer tomography views were obtained to see and interpret the section views of the alloy and composite foam. Compression tests were carried out to evaluate the mechanical behaviour of the foams under static loading. Results show that, the metal foam with % 0.5 B4C reinforcement has the greatest compression strength and the alloy foam has the lowest compression strength. The ceramic content especially %0,5, increased the compressive strength and the toughness of the foam.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Fuat Medik Talha Sunar Melik Çetin Mustafa Yasar Levent Turhan

In this work Cu-Zn-Sn alloy which shows shape retention property was chosen and tested to determine shape retention and other properties. Firstly, elements of the alloy were mixed in required proportions (Cu-%30Zn-%5Sn). The alloy was melted in 1100ºC. Then the product was exposed directly to sudden cooling over the melt spinning unit while it is still melt. Thus, the formation of martensite phase was provided in the microstructure of alloy. The specimens were heat treated at different temperatures and examined for shape memory. The microstructures of the specimens were examined by optical, scanning electron microscopy (SEM) and X-ray microanalyses by EDX. SEM and X-Ray results show that the material constitutes β'-phase and meanwhile by means of plane that was seen in analyse of diffraction x-ray pattern it was held down that the material has 18R and 9R orthorhombic crystal structure.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Talha Sunar Melik Çetin

Processes for the preparation and casting of alloys by using resin sand molding method and heat treatment of cast parts in gas protected atmosphere, alloy preparation and casting conditions and ruthenium investigations, casting conditions, gouging design and microstructure relations, phase formation due to alloy elements and mechanical properties, microstructure relationships, cast magnesium alloys in aviation and automotive applications.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Ali KALKANLI

During the cutting process, this arc occasionally occurs between the throttle nozzle and the electrode and is distorted in the form of the exit hole of the plasma for other reasons. Distortion in the form of the plasma flow hole disturbs the plasma arc and the compressed air flow surrounding the plasma arc, which in turn affects the cutting quality negatively. In this study, we investigated the possibility of reusability(recycling) by filling the wear parts of worn down nozzles with silver containing solders. For this purpose, the wear zones were machined to a diameter 6 mm and a depth of 3 mm, and then solder fillings containing silver were made on the region discharged by oxy-gas flame. The filling area was machined by original drilling with a diameter of 1.6 mm. Throttle nozzle filled with solders containing silver, 2%, 20% and 40% were used for cutting 5 mm thick sheets. Cutting operations of 1 meter length were carried out at a cutting speed of 1 m/min at a current of 50 amperes and a material loss per 10 meters was measured weight and geometrically. The results obtained were compared with the material losses in the copper throttle nozzles.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Ozkan Eski Ayse Yayli Eyuboglu Serkan Islak

Boric acid (H3BO3) solutions, consisting of boric acid powder, ethanol and the other agents, are widely used in eye and ear drops in pharmacy due to their antiseptic and antifungal properties. Boric acid and boric acid solutions, composing of boric acid-agents-ethanol mixture, were experimentally characterized using FT-IR and NMR chemical shift spectra. The prepared solutions proved to be applicable in the field of healthcare with its antiseptic, antifungal and astringent properties.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Tuba Ozdemir Ali Unsal Keskiner

In this study, the super alloy Hastelloy C22 abrasion process was conducted with a copper electrode in electro erosion machine tools. The parameters used in the experimental study were three different pulse durations (10, 20 and 30 μs), waiting time (5, 10 and 15 μs) and discharge currents (5, 10 and 15 amps). As a result of the work done, the minimum mean surface roughness value was measured as 20 μs in the pulse duration, 10 μs in the wait time and 2.86 μm in the 5 amp current. The highest average surface roughness value was found to be 10 μs, 10 μs in the waiting period and 4.07 μm in the 15 amperes current.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Engin Nas Hasan GÖKKAYA Sitki Akincioglu Gulsah Akincioglu

In this study, the effects of boron carbide (B4C) addition on mechanical and physical properties such as microstructure, hardness and density of hot pressed copperboron carbide (Cu-B4C) composites were investigated. To improve the mechanical properties of commercial copper (C) powders having a particle size of 40μm, B4C having a particle size of 40μm, of 2,5, 5, 7,5, 10% by weight was added. Cu-B4C composites were sintered to argon atmosphere at 6500C, 7500C and 8500C for 4 minutes. The electrical conductivity values of the sintered products were measured after examination with the presence of B4C, optical microscope, X-ray diffraction analysis technique and SEM-EDS. In the images obtained, B4C was found to be homogeneously dispersed in the copper matrix. As the ratio of B4C increased, the hardness of the composites increased and the density decreased.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Ozkan Eski Serkan Islak Cigdem Urayli

In this study, Deep cryogenically treated (-145 ᵒC) (H0) and untreated Hastelloy C22 Super Alloy (H1) were etched with a copper electrode on an electro erosion discharge. The parameters used in the experimental study were determined as three different durations (10, 20 and 30 μs), waiting time (5, 10 and 15 μs) and discharge currents (5, 10 and 15 amperes). As a result of the work done, the lowest surface roughness value was measured as 2.20 μm in 20 μs sweep time, 10 μs waiting time and 10 amperes current.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Engin Nas Sitki AKINCIOGLU Hasan GÖKKAYA Gulsah AKINCIOGLU

In this study, the wear behavior of hot rolled AZ31 and AZ31-X wt% La Mg alloys were investigated. After the microstructure characterization, hardness and wear tests, the effect of La on the wear resistance of AZ31 Mg alloy were reported. Hot Rolling process introduced the twins and DRXs on the microstucture wherein the changing of grain boundaries density impart wear resistance to AZ31 Mg alloy.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

İsmail Hakkı Kara Hayrettin Ahlatçı Yunus Türen Yavuz Sun Harun ÇUĞ Mehmet Ünal

In this study, AlSi12 alloy and alloys produced by Mg addition at different ratios (%2 and 4%) were manufactured by pressurized casting method. Homogenization of 520 °C was applied to the produced alloys using electric resistance furnace. Wear behaviors were determined on the data obtained from experiments on the pin-on-disc type abrasion device. DIN 2379 quality cold work tool steel were used as a counter materials during the wear tests. Experiments were carried out at a shear rate of 0.5 m/s at a shear distance of 9000 m under two different loads (10-20 N). The test results were determined by measuring the weight loss of the samples. In order to determine the wear characteristics after the abrasion tests, the worn surfaces were examined with a SEM. The addition of Mg has resulted in significant improvement in abrasion resistance. It has been found that Mg2Si phases which may occur in the structure by Mg addition increase the abrasion resistance of the alloys. When the SEM photographs of the worn surfaces were examined, it is seen that the wear is in the form of groove formation and part plaster, which indicates that it is the adhesive wear characteristic.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Engin ÇEVİK S. Yasin Harun ÇUĞ D. Caliskan S. Gullu T. Cayir

Many techniques are utilized to optimize the parameters of the controllers of dynamical systems. One of these controllers is the proportional integral derivative (PID) controller. The Dc-motor is one of the dynamical systems that have many precise applications. These applications can be achieved by appropriate position and speed controlled systems. In this study the optimization of the gains of the PID controller and the optimization of DC-motor position control is studied. The study focuses on the comparison between the Genetic Algorithm (GA), and the Particle Swarm Optimization (PSO). The PSO algorithm is modified to adapt the considered case study. Required responses performance specifications are introduced in order to be the inputs of both optimization methods. Actual responses performance specifications are obtained by both optimization techniques. The resultant specifications are compared to each other.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Aysha Ali Babak Daneshvar Rouyendegh Adel Agila

In this work, synthesis of TiC powder was carried out at relatively lower temperatures. Titanium dioxide (TiO2) was used as starting material and high purity and nano-sized active carbon as reductive agent. The obtained powder product was subjected to mechanical activation which is for both to make the semi-product more unstable and to decrease the conversion temperature relatively. Homogeneously mixed powders were pressed in a steel die and then the density of green sample was increased with the help of CIPing. In order to determine the conversion temperature, experiments were carried out at three different temperatures under Ar at 1250-1350° for 2h. XRD, SEM and EDS analyses were performed for all yield powders, and the conversion rates were evaluated whether was achieved or not. When the XRD analyses was handled, it could be seen that almost all TiO2 was stayed as stable and no transformation occurred at 1250 °C and 1300 °C. This situation was supported in SEM and EDS analyses. The XRD results showed fully converted TiC structure at 1350 °C. The EDS analysis that the particles were composed of Ti and C elements. Almost fully conversion of Ti2O to TiC powder was achieved at relatively lower temperatures.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Fatih Caliskan Yunus Emre Antika Turgay Tehci Okay Çalışkan

In this research, sliding wear behavior of Cr2O3 (Metco 6156) coating, deposited onto AISI 420 specimens prepared in a cylindrical form (Ø25x8 mm) using atmospheric plasma spray (APS) methods, was evaluated in water environment. For this purpose, Cr2O3 powder, obtained from Sulzer Metco with commercial code Metco 6156 was deposited on AISI 420 stainless steel substrates. Wear mechanisms were interpreted using SEM analyses and 3D profilometer measurements of the samples worn in aqueous media. Adhesive wear behaviors of the coating were comparatively evaluated for dry and aqueous conditions using the same test parameters. The average friction coefficient value was found as 0.3 under dry conditions, whereas this value was found to be nearly 30% lower after the tests in water. SEM micrographs of the worn surfaces show that, the effect of plastic deformation was reduced in water. Also, the amount and lengths of the cracks forming on the worn surface were found to be lower than those of dry conditions, and such cracks resulted in fatigue induced de-bonding.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Y. Kucuk Mustafa Sabri Gök Mecit Oge