热处理工艺对挤压变形ZK60镁合金组织与力学性能的影响

采用硬度检测、拉伸实验、金相分析、TEM分析等方法测试和分析了ZK60合金在铸态、挤压态、固溶态及T5和T6时效态下的硬度、强度和显微组织等。结果表明：ZK60镁合金在塑性变形和不同热处理状态下硬度和强度等力学性能变化明显。经过挤压和T5热处理后，ZK60合金的硬度和强度都大幅度提高。ZK60合金挤压后进行T5处理，其强度要比T6处理的强度明显要高，这与T5状态下合金中析出强化相分布更加密集和细小有关，T6热处理时，由于第二相尺寸以及相互间距都较大，因此强化效果反而不如T5状态。

Effects of heat treatment on microstructures and mechanical properties of ZK60 magnesium alloy

The hardness test, tensile test and microstructure analysis were used to investigate the properties and structure variation of ZK60 alloy in as-cast, extrusion, solid solution and aging states. The results show that the hardness and strength of ZK60 alloy increase obviously after extrusion and T5 treatment. The hardness and strength of ZK60 alloy under T5 condition are higher than those under T6 condition because the second phase precipitated during the aging process is finer and more dispersive under T5 condition than that under T6 condition. The dispersed precipitated phase and dislocations under T5 condition lead to higher mechanical properties for ZK60 alloy.