高锌铝基合金等温处理过程中组织的演变

Structure Formation of High Aluminum Zinc-Based Alloy During Isothermal Treatment

对高锌铝基ZA27合金重新加热到固液两相区进行等温处理,研究了等温处理过程中组织的变化,并对有关组织的成分进行了测定.结果表明,等温处理时随时间的延长,共晶组织中的低熔点富Znη相熔化,Zn原子向初生晶内部扩散.保温20 m in时,初生晶粒由铸态时的等轴晶变为近球状晶,晶粒中的η相有熔化现象.

The microstmctures of ZA27 alloy was investigated during isothermal treatment at solid-liquid phase region, and the compositions of some structures were examined by EDXA. The results indicate that low-melting Zn-rich η -phase in eutectic melt, and Zn atom diffuses toward the primary grain core with the increase in time. When isothermally treated for 20 min, the primary grains change from the as-cast equiaxed grains to spheroids, and the η-phase in grains melts.