Microstructures formation, distribution of tin element and properties of CuSn10P1 alloy during controlled by melt cooling

Abstract

In this paper, the CuSn10P1 alloy controlled by melt cooling stage was carried out through the enclose cooling slope channel (ECSC for short) and similar isothermal collection of crucible, meanwhile the microstructure element distribution of CuSn10P1 alloy were studied. The result shows that the liquid metal quickly cools down to the solid-liquid temperature range under the chilling effect of slit cooling channel. The primary phase rapid nucleation and growth, the distribution characteristic of the tin mass fraction of the core is lower and the outer ring is higher. The preheating crucible was used to collect the slurry which prepared by the ECSC, the latent heat of crystallization and volume temperature effect were used to carry out short-time similar isothermal treatment. With the process of similar isothermal treatment, the primary phase is aged and changes to the spherical shape, while the tin element diffuses into the primary phase from the liquid. The semi-solid slurry with the above-mentioned microstructure feature was subjected to squeeze casting to obtain shaft sleeve parts. The ultimate tensile strength and elongation of the shaft sleeve parts increased by 22% and 93%, respectively, compared with the liquid squeeze casting. This is attributed to the grain refinement and homogeneity of macroscopic concentration distribution of tin elements in CuSn10P1 alloy.