M.Sc Tezi Görüntüleme

      The hardness of the Zn-Al-Cu alloys increased continuously with increasing copper content. The tensile strength of the alloys also increased with increasing copper content up to 4% Cu, but above this level it decreased as the copper content, increased. It was observed that the volume loss due to wear of the alloys showed a linear change with the test duration and the applied pressure. It was also observed the copper content had no significant effect on the wear rate and operating temperature of these alloys.

      Distinct scratches and smearing were observed on the wear surface of samples of the alloys tested. Metallographic examinations revealed three distinct regions in the surface material of the wear samples. These were a smearing layer, a flowed region and the unchanged material with original microstructure. It was observed that as the applied pressure increased the thickness of the smearing layer and flowed region increased. The uppermost layer had the highest, while the flowed region showed the lowest microhardness values. Formation of these different layers was related to the microstructural changes, which occurred due to frictional heat and heavy plastic deformation. As a result of these observations it was concluded that adhesion and abrasion are the main mechanisms for the wear of Zn-Al-Cu alloys under dry sliding condition.

      Key Words : Zinc-Aluminium-Copper Alloys, Pin-on-Disc Machine, Dry Sliding, Wear