Investigation of characteristics of tin-based white metals as a bearing material

The microstructure of tin-based white metals consists of a soft solid solution matrix and two intermetallic compounds (Cu6Sn5, SbSn) that are harder than the matrix. This special microstructure qualifies these alloys as a bearing material. In the present study the effect of solidification rate and heating on microstructure and hardness of tin-based white metals is investigated. The results show that rapid cooling suppresses formation and growth of SbSn cuboids and increases hardness. Heating makes the precipitate’s corners round. Since resistance to wear is the most important property of a bearing metal, a comparison between pin on disk wear resistance of ASTM B23-alloy 2 and alloy 3 has also been conducted. Results show that alloy 2 has more resistance to wear in dry sliding condition.