镁合金真空低压消失模铸造影响因素及充型能力的研究

介绍了一种新的真空低压消失模铸造工艺,分析了该工艺的工作原理和影响因素,并采用窗体及电机壳体模样测试了AZ91D镁合金在该工艺条件下的充型能力。研究表明：充型气体的气压与流量、泡沫模样的密度与裂解特性、涂层厚度及透气性、浇注温度、真空度等是镁合金真空低压消失模铸造过程中的主要影响因素。窗体和电机壳体成功浇注试验证明了真空低压消失模铸造新工艺大大提高了镁合金的充型能力,消除了重力下消失模铸造镁合金充型能力差、易形成浇不足和冷隔缺陷的缺点。

Study on the Influencing Factors and Filling Ability of Magnesium Alloys in the Lost Foam Casting(LFC) with Vacuum and Low Pressure

A newly developed low-pressure expendable pattern casting process is introduced and its basic principleand influencing factors are analyzed. The filling ability of AZ91D magnesium alloy was also examined with electromotor frame and window pattern via this process. The experimental results indicate that main casting process parameters contain pressure and flux of filling gas, pyrolysis characteristics and density of foam pattern, thickness and permeability of coating, pouring temperature and vacuum degree. The success of casting motor shell and window pattern demonstrates the new technology can greatly improve the filling ability of the magnesium alloy, consequently eliminates the misrun and cold shut in gravity LFC process.