SEARCH RESULT

In this work, the wear resistance behavior of GG-25 gray cast iron was investigated. Three specimens with different austempering time (120, 90 and 60 minutes) and one specimen, which is not austempering, were used. With this manner it has been tried to examine the effect of the parameters of austempering process on each specimen. Pin-on-disc wear resistance test with one loads (20N) on every specimens has been applied according to of ASTM 99 standards. SEM to observe the microstructures characterized the austempered specimens. In addition, brinnel hardness test was applied. With the results of the wear resistance test, as the austempering time increased, wear resistance also increases.

International Iron & Steel Symposium
UDCS

Abdulsamet YILDIRIM Yunus Türen Hayrettin AHLATCI Yavuz Sun Mustafa GUÇLU Hamza Serhat AYDEMIR Mehmet Sami TAKVA

In this study, the effect of C addition on the corrosion behavior of wire rods of 5.5 mm in diameter was investigated. The horizontal and vertical cross sections of the wire rods with 0.7, 0.8, 0.9 C ratio were taken during the metallographical process. The microstructure of the examined specimens was examined by light optical (LOM) and scanning electron microscopy (SEM). Hardness test of steel containing 0.7- 0.9 C was carried out in shimadzu brand micro hardness tester. Corrosion tests of the prepared samples were evaluated according to both the weight loss and the Potentiodynamic Polarization measurements in 3.5% NaCl solution. Despite the increased hardness of the specimens examined, the corrosion resistance decreased. This can be caused by inclusions in the microstructure.

International Iron & Steel Symposium
UDCS

Medine Kilinc Gulheser Dogancik Yunus Türen Yavuz Sun Hayrettin AHLATCI İbrahim AFŞAR Serhat ÖZDEMİR Hüseyin Koymatcık Hüseyin Zengin

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

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

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

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

Aşınma sürtünen yüzeylerde malzeme kaybı olarak tanımlanır. Aşınmayı tamamen önlemek ise olanaksızdır. Aşınma büyük ekonomik kayıplara neden olduğundan üzerinde yoğun araştırmalar yapılmaktadır. Malzemelerin aşınma mekanizmaları, adhesiv, abrasiv, erozif ve korozyonlu aşınma şeklindedir. Her bir aşınma testi farklı cihazlar yardımı ile yapılabilmektedir. Bu çalışmada bu aşınma mekanizmalarının hepsinin birden test edilebiliceği tek bir cihazın tasarımı ve imalatı yapılmıştır. Tasarlanan aşınma cihazında 2.2 KW’lık, 1450 d/dk’lık ve 0.25 KW’lık 915 dev/daklık üç faz ile çalışan alternatif akım motorları, 2.2 ve 0.4 KW’lık inverterler, hareketin otomatik olarak sonlandırması için spiral plastik yay tahrikli limit switch, karşı malzeme olarak dolu halka blok, aşındırıcı kaplı tambur kullanılmıştır. Wear is defined as the loss of materials at the rubbing surfaces It is impossible to completely prevent wear. Wear causes huge economic losses so intensive research is being conducted in Wear. Wear mechanisms of materials are adhesive, abrasive, erosive and corrosive wear shape. Each abrasion test can be performed with the aid of different devices. All of the wear mechanism in this study may be tested once the design and manufacture of a single device is made. In this study, three-phase alternating current motors working at 2.2 KW-1450 rev/min and 0.25 KW-915 rev/min, inverters with 2.2-0.4 KW, spiral plastic spring actuated limit switches for wear process automatically terminated, abrasives coated drum and metal block as counter device is used.

International Symposium on Industrial Design Engineering
ISIDE14

Öznur ŞİŞMAN Onur ÖZER Ahmet KELEŞ Yiğit GÜMÜŞBOĞA Emre TABAN Yavuz Sun Hayrettin AHLATCI