等温热处理对AM60-1Si合金半固态组织的影响

Effect of Isothermal Heat Treatment on the Semi-solid Microstructure of AM60-1Si Alloy

采用半固态等温处理法研究保温温度和保温时间对AM60-1Si合金半固态组织的影响规律。研究结果表明:AM60-1Si合金的半固态组织经历了近球状晶粒的形成、晶粒的球化和球晶的长大过程;随着保温温度的增加和保温时间的延长,初生α-Mg固相颗粒的尺寸先减小、后增大;605℃时保温45 min可获得晶粒细小、分布均匀且球状的半固态组织;在等温处理的过程中,汉字状的Mg_2Si相变为近球状。

The effect of isothermal heat treatment on the microstructure of semi-solid AM60-1Si alloy is investigated. The results show that the semi-solid microstructure evolution of AM60-1Si alloy experiences three stages,i. e.,formation of globular particles,spheroidization and coarsening,during isothermal heat treatment process. With the increase in holding temperature and holding time,the size of primary α-Mg phase decreases at first and then increases. The fine well-distributed globular semi-solid microstructure can be obtained at 605 ℃ for 45 min. The Mg_2Si phase changes from initial Chinese script shape to polygon shape during isothermal heat treatment.