Mg-8Zn-2Si-0.5Ca合金热处理前后的组织性能

Microstructure and Hardness of Mg-8Zn-2Si-0.5Ca Alloy Before and After Heat Treatment

研究了Mg-8Zn-2Si-0.5Ca合金及其热处理后的组织和性能。结果表明:铸态下合金由α-Mg相、MgZn相、Mg2Si相和CaSi2相组成。Mg2Si的形状为块状,颗粒较细小,Mg2Si的晶核为CaSi2相。固溶处理后,合金中原来呈骨骼状分布的MgZn相明显减少,并变得细小。固溶处理未能使Mg2Si相溶入基体组织中。时效处理后固溶到基体中的MgZn相以细小的弥散相析出。经固溶和时效处理后,合金的硬度明显提高。

Microstructure and hardness of Mg-8Zn-2Si-0.5Ca alloy after heat treatment were investigated. The results show that the alloy is comprised of α-Mg,MgZn,Mg_2Si and CaSi_2 phase;the Mg_2Si appear as blocks and the particles are tinny; CaSi_2 phase is as the core of the Mg_2Si grains; after the solid solution treatment, the skeletal MgZn phase decreases clearly and its size becomes small;the solid solution treatment can′t make the Mg_2Si phase dissolve into the α-Mg matrix; the dissolved MgZn phase during the solid solution treatment precipitates tinny and dispersed phase after aging;after the solid solution treatment and aging, the hardness increases greatly.