镁合金AZ91D真空压铸的组织与性能

Microstructure and Mechanical Properties of Vacuum Assisted High Pressure Die Casting of AZ91D Magnesium Alloy

对镁合金AZ91D真空压铸下的组织与性能进行了研究。结果表明，真空压铸可以明显改善AZ91D合金组织中的孔洞分布，。提高铸件的密度。对铸件进行热处理（T4）后，铸件表面气泡相对于普通压铸而言有明显改善，可以热处理。热处理后（T4和T6），由于AZ91D具有固溶强化和时效强化效果，合金的性能相对于压铸态有大幅度的提高。

The effect of vacuum assistance on the porosity distribution and mechanical properties of the AZ91D Magneium Alloy was studied. Selected specimens were also subjected to T4 and T6 tempering treatment to evaluate the effects on the mechanical properties. It was found that the volume of porosity and the pore sizes in the castings were significantly reduced by using vacuum assistance during die casting. As a result, the density were improved markedly. After heat treatment （T4）, vacuum assisted die cast parts showed much less surface blistering when compared to conventional die cast parts, demonstrating that vacuum assisted die castings are promising for heat treatment. Mechanical properties after T4 and T6 tempering got marked improvement as AZ91D can be solution and aging strengthened while vacuum assisted die casting gave it this opportunity.