半固态等温热处理对ZA12合金组织和性能的影响

将初生相为枝晶形态的常规ＺＡ１２合金铸锭重新加热到半固态进行等温热处理，可获得具有良好触变性的非枝晶组织合金。文中对半固态热处理工艺参数与显微组织之间的关系进行了研究，并对铸态和经过半固态热处理的两种材料的半固态形性能以及成形制品的力学行为进行了试验对比。结果表明，经适当工艺热处理后，ＺＡ１２合金可以实现半固态成形，不仅成形抗力低，液相偏析少，且提高了制品的力学性能。

Effect of Semi-solid Isothermal Heat Treatment on the microstrures and Properties of ZA12 Alloys

The non-dendritic structure ZA12 alloy with ideal thixotropic behaviour was obtained by isothermal heat treating the conventional ingots in semi-solid states- The relationship between the parameters of heat treatment and the microstructure was investigated. Then the semi -solid forming behaviour of both as cast and heat treated metals as well as the mechanical behaviour of the formed products were tested and compared. The results show that after proper heat treating in semi-solid states,the ZA12 alloy can be formed in the semi-solid states with the low forming force and little liquid phase segregation. In addition,the mechanical behaviour of the formed products was also improved.