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对ZK60镁合金凝固过程中有电磁搅拌和无磁场条件下的凝固组织进行对比,利用光学显微镜、显微硬度计、X射线衍射仪和扫描电镜分析固溶处理后的ZK60镁合金析出相。结果表明:低频交变磁场下铸态合金的显微组织主要由初晶Mg基体和非平衡共晶组织(Mg+MgZn+MgZn_2)组成;和无磁条件下的显微组织相比,低频交变磁场下晶界网状共晶组织更加细小,晶粒分布更加均匀。固溶处理有利于第二相粒子的溶解,固溶处理前,低频交变磁场条件下铸态组织与无磁场条件下的铸态组织相比晶粒明显细化,而固溶处理后前者比后者晶粒分布更加均匀;不同固溶处理时间下的硬度曲线均呈单调下降趋势,相同温度下,固溶时间越长,硬度值越小;相同固溶处理制度下,低频交变磁场条件下的试样硬度值低于无磁场条件下的硬度值;低频交变磁场条件下合金的力学性能均高于无磁场条件下的力学性能。
The solidification microstructure of ZK60 magnesium alloy during electromagnetic solidification without magnetic field was compared. The precipitated phase of ZK60 magnesium alloy after solution treatment was analyzed by optical microscope, microhardness tester, X-ray diffraction and scanning electron microscope. The results show that the microstructure of the as-cast alloy under low frequency alternating magnetic field mainly consists of primary Mg matrix and non-equilibrium eutectic microstructure (Mg + MgZn + MgZn_2); Compared with the microstructure without magnetic condition, Grain boundary reticular eutectic microstructure becomes more finer and the grain distribution is more uniform. Solution treatment favors the dissolution of the second phase particles. Before the solution treatment, the as-cast microstructure of the as-cast microstructure is obviously refined compared with the as-cast microstructure under the condition of low frequency alternating magnetic field, while the former ratio The latter is more uniform distribution of grain size; hardness curve at different solution treatment time showed a monotonous downward trend, the same temperature, the longer the solution time, the smaller the hardness value; the same solution treatment system, low frequency alternating magnetic field conditions Under the condition of low frequency alternating magnetic field, the mechanical properties of the alloy are higher than the mechanical properties under the condition of no magnetic field.