镁合金压铸工艺的数值模拟

来源期刊：中南大学学报(自然科学版)2006年第5期

论文作者：于彦东 蒋海燕 雷黎 曾小勤 翟春泉 丁文江

文章页码：867 - 873

关键词：镁合金;压铸;数值模拟;缩孔;气孔

Key words：magnesium alloy; die casting; numerical simulation; macro porosity; gas porosity

摘    要：运用有限元模拟软件对镁合金AZ91D压铸零件的充型和凝固过程进行数值模拟,分析完全凝固后存在于铸件中的缩孔及气孔缺陷的体积分数;以铸造缺陷尺寸为标准,研究压射速度、浇注温度及模具初始温度3种压铸工艺参数对铸件质量的影响,获得优化的压铸工艺参数,为减少镁合金零件的缩孔和内部气孔、提高压铸件致密度和表面质量提供依据。模拟结果表明,铸件中存在最小缺陷的最佳压铸工艺参数是:冲头压射速度为2.4 m/s,浇注温度为655℃,模具初始温度为200℃;最终获得的缩孔的体积分数仅为1.909 80%,气孔体积分数为1.766 83×10^-6。

Abstract: The numerical simulation of filling and solidifying process of magnesium alloy AZ91D die casting was performed with finite element software. The volume fractions of macro porosity and gas porosity existing in the die casting were analyzed. The influence of injection speeds, pouring temperatures and mold initial temperatures on the quality of die casting was investigated by taking the size of casting flaws as standard. The best technological parameters, under which the macro porosity and gas porosity in the magnesium parts can be reduced and the density and surface quality of die castings can be increased, were obtained. The results show that the optimum condition which makes the flaws in the die casting least is as follows: injection speed of 2.4 m/s,pouring temperature of 655℃, mold initial temperature of 200℃. Finally the maximum volume fraction of macro porosity is only 1.909 80%, while that of gas porosity is 1.766 83×10^-6.