Effect of Sn and Pouring Temperature on the Hardness and Wear Resistance of CuSn7Pb7Zn3

Although the bearings are part of the assembly in the set of moving parts, they must endure a variety of axial and radial forces. In this way, their hardness and wear resistance should be suitable. On the other hand, the chemical composition and the pouring temperature of the casting are two important factors for the formation of proper microstructure and, therefore, favorable properties. The purpose of this study was to study the effect of tin and pouring temperature (casting temperature) on microstructure and total hardness and weight loss due to wear of CuSn7Pb7Zn3 bronze for use in the bearing. For this purpose, first, the CuSn7Pb7Zn3 bronze was melted in a transistor induction furnace and then the microstructure, hardness and wear resistance in sand mold in four different casting conditions including casting temperatures of 950C and 1200C, and tin values of 2.5 and 7.0 Wt% compared. The results indicate that the sample that is pouring at 950C and its tin content is 7.0% by weight, with a hardness of 77 Brinell and a weight loss of 2.9 mg is most appropriate because the contents of solid solution phase and lead phase, and intermetallic compounds, are more and more comparable in dispersed distribution.

Bearing, Bronze, Casting temperature, Overheating, Tin