Tribological behaviour of tin bronze alloys produced by different casting techniques

Abstract

In this study the hardness and wear resistance behaviour of tin bronze alloys produced by die and sand mould casting were investigated. The alloying element (Sb) was added with percentage of (3,5 and 8) wt. % to tin bronze alloys. The wear tests were performed using a pin on disc. The applied load was (10, 20, 30) N, rotational speed was constant equal to 250 rpm and the time (5,10,15) minute. Results were evaluated using losses in weight. Every worn surface was tested by SEM and the wear properties of bronze materials are discussed. It was concluded that CuSn12 material produced by die mold casting technique had higher hardness than the material produced by sand mold casting technique, due to rapid cooling, also after the wear test, wear loss of CuSn12 alloy produced by die mould casting technique was lower due to its higher hardness. In addition to the hardness for tin bronze + 8 wt% Sn increased by 24.8 % for sand casting and 26.7 % for die casting. The results of scanning electron microscopy of worn surface were characterized by wear grooves run parallel to the sliding direction, removes the particles, smearing of Sn phase and plastic deformation. In addition to increasing in the rate of antimony an improvement in the in the wear track, where the rate of deformation and cracks decreases, especially when increasing Sb up to 8%.