Mg-Al系镁合金半固态坯料制备及触变挤压研究

Preparation of Mg-Al Series Magnesium Alloy Semi-solid Billets and its Thixo-extrusion Forming

采用拉伸试验机、金相显微镜和等径道角挤压等试验方法对Mg-Al系镁合金半固态坯料制备及触变挤压过程进行了研究。结果表明,等径道角挤压工艺对Mg-Al系镁合金有很好的应变诱导效果。经过等径道角挤压的Mg-Al系镁合金力学性能高,晶粒细小。等径道角挤压+等温处理方法制备的Mg-Al系镁合金半固态坯的微观组织晶粒细小,球化程度高,微观组织非常均匀。生产的AZ61、AZ80、AZ91D和AM60镁合金角框零件的微观组织细小,抗拉强度分别达到306.8、308.3、299.8、321.6MPa。伸长率分别达到21.6%、28.4%、14.6%和29.6%。

By means of tensile testing machine,metalloscope and equal channel angular extrusion(ECAE) testing,preparation of Mg-Al magnesium alloy semi-solid billets and its thixo-extrusion forming were investigated.The results show that desirable strain induced effects can be obtained by ECAE.After Mg-Al magnesium alloy was processed by ECAE,mechanical properties was increased with the refinement of grain size.Semi-solid billets prepared by new SIMA were characterized by fine grains,desirable spheroidization and homogeneous microstructure.In contrast,semi-solid billets prepared by direct isothermal treatment were characterized by coarse grain and terrible spheroidization.High mechanical properties and fine grains occur in angle frame components manufacture by thixo-extruding new SIMA prepared Mg-Al series semi-solid billets including AZ61,AZ80,AZ91D and AM60.Tensile strengthes of angle frame components reach 306.8,308.3,299.8 and 321.6MPa,respectively,and elongations are 21.6%,28.4%,14.6% and 29.6%,respectively.