Ahmet MASLAVİ, Alim KAŞTAN, Hüseyin ÜNAL

Sentetik Mika Takviyeli Poli-tetra-flor-etilen Polimer Kompozitin Tribolojik Özelliklerine Uygulanan Yükün ve Kayma Hızının Etkisinin Belirlenmesi

Saf PTFE endüstride düşük basınç keçeleri olarak kullanıldığında aşırı aşınma göstermektedir. Bu aşınma problemini azaltmak için sentetik mika (SM) takviyeli poli-tetra-flor-etilen (PTFE) polimer kompoziti alternatif malzeme olarak seçilmiş ve tribolojik performansları araştırılmıştır. Tribolojik deneyler çelik disk üzerinde kompozit pim olacak şekilde dizayn edilmiş aşınma test cihazında gerçekleştirilmiştir. Deneylerde 10, 20, 40 ve 100 N olmak üzere dört farklı yük ve iki hız (0.5 ve 1.5 m/s) kullanılmıştır. Deneyler sonucunda sentetik mika takviyeli PTFE kompozitin (PTFE-SM) sürtünme katsayısı, pim ve çelik disk sıcaklığı ile spesifik aşınma hızı belirlenmiştir. Uygulanan yükün ve hızın artması ile pim ve çelik disk yüzey sıcaklıkları artarken spesifik aşınma hızı da artmış fakat sürtünme katsayısı azalmıştır. Kompozitin en düşük ve en yüksek sürtünme katsayısı değerleri sırasıyla 0.17 ve 0.25 olarak tespit edilmiştir. Benzer şekilde spesifik aşınma hızı aralığı olarak en düşük 0.217x10-15 m2/N ve en yüksek 25x10-15 m2/N olarak belirlenmiştir. Kompozitin aşınma yüzey incelemeleri optik mikroskop ve taramalı elektron mikroskobu (SEM) kullanılarak gerçekleştirilmiştir. Mikroyapı incelemeleri sonucunda çelik disk yüzeyinde ince film tabakası oluştuğu belirlenirken 100 N yük ve 1.5 m/s kayma hızında kompozit pim yüzeyinde çatlaklar olduğu tespit edilmiştir.

Determination of the Effect of Applied Load and Sliding Speed on the Tribological Properties of Synthetic Mica Reinforced Poly-Tetra-Fluoro-Ethylene Polymer Composite

Pure PTFE shows extreme wear when used in industry as low pressure seals. In order to reduce this wear problem, synthetic mica (SM) reinforced poly-tetra-fluoro-ethylene (PTFE) polymer composite was used as an alternative material and its tribological performances were investigated.In this study, tribological performances of synthetic mica (SM) reinforced poly-tetra-fluoro-ethylene (PTFE) polymer composite were investigated. Tribological experiments were carried out in a composite pin-on-steel disc (P-o-D) wear test device designed as a composite pin on a steel disc. Four different loads of 10, 20, 40 and 100 N and two sliding speeds (0.5 and 1.5 m/s) were used in the experiments. As a result of the experiments, the friction coefficient, pin and steel disc temperature and specific wear rate of the synthetic mica reinforced PTFE composite (PTFE-SM) were determined. As the applied load and sliding speed increased, the pin and steel disc surface temperatures increased, while the specific wear rate increased, but the friction coefficient decreased. The lowest and highest friction coefficient values of the composite were determined as 0.17 and 0.25, respectively. Similarly, the minimum specific wear rate range was determined as 0.217x10-15 m2/N and the highest 25x10-15 m2/N. Wear surface examinations of the composite were carried out using optical microscope and scanning electron microscope (SEM). As a result of the microstructure investigations, it was determined that a thin film layer was formed on the surface of the steel disc, and cracks were observed on the surface of the composite pin at the load of 100 N and a sliding speed of 1.5 m/s.

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