影响消失模铸造AZ91D镁合金振动凝固组织性能的因素

Factors of Affecting the Microstructure and Properties of AZ91D Magnesium Alloy in Lost Foam Casting under Vibrating Solidification

系统地研究了影响消失模铸造AZ91D镁合金在机械振动下凝固组织性能的各种因素。结果表明,振动下凝固可以显著改善消失模铸造AZ91D试件的组织性能,其影响因素包括振动力、浇注温度、试样厚度等;将振动凝固消失模铸造AZ91D试件施于半固态下的等温热处理,可进一步提高试件的性能。在消失模铸造中,采用三维变频振动紧实台实施散砂的紧实,且在实型(泡沫模样)下浇注,振动凝固不需要增加另外的振动凝固装置、也不会因振动产生铸型坍塌缺陷,故具有良好的操控性和实际应用前景。将振动凝固与半固态等温热处理工艺结合起来应用于镁、铝合金的消失模铸件,可以综合振动凝固细化晶粒与半固态等温热处理球化晶粒的优势,有望成为获高性能消失模铸造镁、铝合金零件的好方法。

All factors that may influence microstructure and properties of AZ91D alloy in lost foam casting (LFC) under vibrating solidification were investigated systematically.The results shown that the microstructure and properties of the sample of AZ91D alloy in LFC could be improved obviously by vibrating solidification,but the influencing factors included vibration force,pouring temperature,thickness of the sample,etc,and the properties of above sample that could be more improved by isothermal heat treatment in semi-solid state.In lost foam casting process,the three dimensional vibration desk was used to compact loose sand and the melt alloy was poured in full cavity (foam model),so the extra vibration solidifying device did not need to be added and also could not cause slump flaw because of vibrating,that has good operability and actual application future.Combing vibration solidification and semi-solid isothermal heat treatment to apply to the LFC of Mg or Al alloy could display the synthetical advantages of the fining grain of vibration solidification and globurizing grain of semi-solid isothermal heat treatment,it may become a good technology which can obtain high property casting part of Mg or Al alloy via LFC.