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通过半固态等温热处理,研究了重熔温度和保温时间对铸造ZC63镁合金半固态组织演变的影响。结果表明:半固态等温热处理能够将ZC63合金中的枝晶组织转变为球状组织,并可获得更加细小、分布均匀的球状颗粒;重熔温度和保温时间对非枝晶组织演变有着重要的影响,提高保温温度或延长保温时间,可加快原始铸锭重熔进程及组织形态的优化,保温温度过高或保温时间过长,试样会发生严重变形,同时球状颗粒易于粗化和长大;非枝晶组织演变是在熔化和结晶的动态变化中完成,主要的演变机制是在等温热处理过程中晶界处的共晶组织向基体溶解,原始组织的粗化、分离、球化以及球状颗粒的合并与长大。ZC63合金半固态触变成形最适合的等温热处理工艺是600℃×30 min。
The effect of remelting temperature and holding time on the microstructure evolution of cast ZC63 magnesium alloy was studied by semi-solid isothermal heat treatment. The results show that the semi-solid isothermal heat treatment can transform the dendritic structure into spherical structure in ZC63 alloy and obtain more fine and uniform spherical particles. The remelting temperature and holding time are important for the development of non-dendritic structure Influence, increase the holding temperature or extend the holding time, can accelerate the original ingot remelting process and the optimization of the organizational morphology. The holding temperature is too high or the holding time is too long, the sample will be severely deformed, while the spherical particles are easy to roughen and grow ; The non-dendritic microstructure evolution is accomplished in the dynamic changes of melting and crystallization. The main evolution mechanism is that the eutectic structure at the grain boundary dissolves into the matrix during the isothermal heat treatment, and the original structure is roughened, separated and spheroidized As well as the integration and growth of spherical particles. ZC63 alloy thixoforming most suitable isothermal heat treatment process is 600 ℃ × 30min.