Mixed RE Modification and Semi-solid Microstructure Evolution of In-situ Mg_2Si/Al-Si Composites
The effects of mixed RE on microstructure in in-situ Mg2Si/A1-Si composite and the semi-solid microstructure evolution of the composites under different temperature were investigated.The result shows that 1.0%(mass fraction) mixed RE can modify primary silicon effectively,the average grain size decreases from 175μm to 55μm;after isothermal heat treatment,the primary silicon grain size decreases first and then increases with the increase of temperature,and α phase in the composites is spheroidized at 560℃.