【摘要】 研究了不同浇注温度下消失模铸造AZ91D在振动凝固和“振动凝固+半固态热处理”条件下组织的变化。结果表明,对不同浇注温度下的消失模铸造AZ91D试样实施振动凝固能细化试样的显微组织,且在浇注温度为740℃、振动力为1.5kN时组织细化效果最好;对经振动和不振动凝固的试样进行半固态等温热处理,两者的组织都得到球化,且随着等温时间的延长,两者的组织都会合并长大,其中半固态等温热处理的较佳工艺为“570℃下保温10min”。更多还原

【Abstract】 Evolutions of microstructure of AZ91D magnesium alloy in lost foam casting at different pouring temperatures under vibration and vibration+semi-solid heat treatment conditions have been observed. The results show that the microstructure of the AZ91D magnesium alloy in lost foam casting can be obviously refined by vibration at different pouring temperatures, and the finest grain size can be observed by vibration force of 1.5 kN at the pouring temperature. The microstructures of both the vibrated and common samples treated by semi-solid isothermal condition can be spheroidized, and the microstructures would be coalesced to growth, in which the optimized semi-solid heat treated parameters are at holding time for 10 min at 570 ℃.更多还原