SEARCH RESULT

Reference materials (RMs) are one of the basic materials used by the laboratories to prove the reliability of their test results. In this research, preliminary studies have been carried out to develop reference materials (RMs) according to ISO 6892-1 tensile testing standard. For this purpose, EN 10130:2006 quality 1 mm thin sheet steel was prepared as appropriate to standard. Homogeneity tests and inter-laboratory comparison tests were performed. Results of these tests and reproducibility criteria that specified in ISO 6892-1 were evaluated to understand the qualification of the produced RMs. It was considered that samples can be accepted as RMs with the application to IAF member organizations.

International Iron & Steel Symposium
UDCS

Betul ERCAN Alper Incesu Engin ÇEVİK Yasin Akgül

In this study, up to 38ppm of boron was added to 4140 steel and the effects of this addition on microstructure and tribocorrosion were investigated. Tribocorrosion behavior was investigated in a 3.5% NaCl solution with a pin on disc method. As a result of the studies, it was found that the hardness and tribocorrosion behavior increased with the addition of boron but these values decreased with the increase in boron amount after 17ppm.

International Iron & Steel Symposium
UDCS

Tayfun AKSOY Engin ÇEVİK Hüseyin DEMIRTAS Yavuz Sun Cemal ÇARBOĞA

Pig iron production costs are very high in blast furnaces where conventional iron and steel production is carried out, and therefore, iron and steel producers seek alternative methods, two of which are the production of sponge iron and iron nuggets. Depending on furnace temperature and waiting time, reduction of magnetite to pure iron results in three products, one of which is Direct Reduced Iron obtained from iron oxide ore in a reducing atmosphere between temperatures of 900-1100 oC. The second product is Transition Direct Reduced Iron (TDRI) obtained at temperatures at which partial melting occurs. The third product is iron nuggets in which complete melting occurs, and metal and slag are separately obtained. The aim of this study was to investigate the effect of biomass waste on iron nugget production from magnetite ore using carbothermic method. Biomass waste was carbonized at 800 °C for 1440 min to obtain a 94.68% C and 0.03% S carbonized product with a thermal value of 8823 cal/g. Composite pellet samples with and an O/C of 0.5, 1 and 2 were treated in a high temperature furnace at 1300 and 1350 °C for 5, 10 and 15 min. Results showed that samples contained Fe and C as well as FeO. Macro images showed that metal-slag separation was not fully achieved and that the product exhibited TDRI properties.

International Iron & Steel Symposium
UDCS

Bayram Bostancı Elif ARANCI ÖZTÜRK Mustafa BOYRAZLI Engin ÇEVİK Zeki Çizmecioğlu

In this study, the effect of boron addition at different ratios (2-38 ppm) on the microstructure and corrosion properties of Cr-Mo steels was investigated. Square cross-sections of the boron containing steels obtained at different ratios measuring 40×40 mm were rolled in three passes, and a deformation of totally 200-300 percent was obtained. The rolled specimens were examined by optical microscopy and corrosion test. Electrochemical potentiodynamic polarisation measurements were taken to evaluate corrosion behaviours of the examined steels. Analysing the potentiodynamic corrosion test results applied to the CrMo steels containing boron at different ratios, it is seen that there has been increase at the corrosion rates when the boron amounts are low.

International Iron & Steel Symposium
UDCS

Cemal ÇARBOĞA Bülent KURT B. Demirel Yavuz Sun Hayrettin Ahlatçı Engin ÇEVİK

Kompozit malzeme genel olarak anayapı içerisinde dağılım gösteren anayapıdan farklı takviye faz ile birleşmesinden meydana gelen bir malzeme sisteminden meydana gelmektedir. Takviye elemanın özelliği, geometrisi, dağılımı ve farklı takviyelerin tane sınır özellikleri malzemenin farklı özellikler göstermesine sebep olur [1]. Genel olarak hızlı ve yüksek üretim kapasitesine sahip olması ve son şekle yakın üretim imkânı sağlaması gibi avantajlarından dolayı basınçlı infiltrasyon tekniği önemli üretim tekniklerindendir. [2] Bu çalışmada, AA6061 matrisli %50 B4C ve SiC partikül takviyesi ile üretilen kompozit malzemelerin mikroyapı ve mekanik özelliklerine matris bileşimi ve basınç değerinin etkisi incelenmiştir. Çelik borular içerisine 50x8 mm ölçülerinde 48 μm ortalama tane boyutuna sahip B4C tozları ve 37 μm ortalama tane boyutuna sahip SiC tozları kullanılarak preformlar oluşturulmuştur. Hazırlanan preformlara, 800 oC’de basınçlı infiltrasyon tekniği kullanılarak 7 ve 8 bar basınçlarda AA6061 alüminyum matrisler infiltre edilmiştir.

International Symposium on Light Alloys and Composite Materials
UHAKS

Kadir GÜNDOĞAN Engin ÇEVİK Alperen R.B. ÖZSARI Safa POLAT

Kompozit malzeme tanım olarak iki veya daha fazla sayıdaki aynı veyahut farklı yapılardaki malzemelerin en iyi özelliklerini yeni ve tek bir malzemede toplamak amacıyla makro düzeyde birleştirilmesiyle oluşturulan malzemeler olarak adlandırılırlar. [1] Metal matrisli kompozitler, metallerin tek başlarına istenilen özellikleri karşılayamadığı alanlarda genel olarak seramik türü takviye elemanları kullanılarak oluşturulan kompozit malzeme grubu olarak adlandırılır. [2] Genel olarak hızlı ve yüksek üretim kapasitesine sahip olması ve son şekle yakın üretim imkânı sağlaması gibi avantajlarından dolayı basınçlı infiltrasyon yöntemi önemli üretim tekniklerindendir. Basınçlı infiltrasyon yöntemi ile metal matrisli kompozit malzeme üretiminde matris malzemesi olarak alüminyum ve magnezyum alaşımları daha geniş kullanım alanı bulmuşlardır. [3] AA2024 alaşımı, alüminyum alaşımları arasında kıyaslama yapıldığında en sert, elastisite modülü ve mukavemet değerleri en yüksek olanlarından biridir. [4]

International Symposium on Light Alloys and Composite Materials
UHAKS

Kadir GÜNDOĞAN Engin ÇEVİK Alperen R.B. ÖZSARI Safa POLAT

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

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

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 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