铸造镁合金旋转喷吹除气的试验研究

The Degassing of AZ91D Mg Alloy by a Spinning Spraying Processing

研究了旋转喷吹技术在AZ91镁合金熔体除气净化处理上的应用。采用减压凝固法考察了旋转喷吹的除气净化工艺的净化效果,确定了最佳的除气时间。利用金相显微镜观察了除气前后合金的微观组织。对除气前后的合金,进行了金属型和低压砂型铸造试验浇注,并对其力学性能进行了测试和比较。研究结果表明,经过30min旋转喷吹除气处理后,能快速显著地降低镁合金中的含气量,AZ91合金金属型和低压砂型试样的力学性能都明显地得到提高,特别是合金的伸长率得到大幅度的提高。

Spinning spraying processing used for degassing treatment of AZ91D Mg alloy was researched. Pressure-reduction solidification is used to assess the efficiency of the degassing process and the optimal degassing time is determined. The mechanical properties and the microstructure of the alloy samples before and after degassing treatment in metal mold casting and in low pressure sand casting were studied,respectively. The results show that the tensile strength of the alloy samples treated by spinning spraying for 30 min can be considerably improved both in metal mold casting and in low pressure sand casting, particularly sharply improved in elongation. Based on the experimental results, it is concluded that the spinning spraying can rapidly and obviously reduce the gas content in Mg alloy, improving the mechanical properties, which is a desirable processing for refining Mg alloy melt.