均匀化热处理对Mg-5Zn-1Mn镁合金导电性能的影响

Effects of homogenizing heat treatment on the electrical conductivity of ZM51 magnesium alloys

通过光学显微镜、扫描电镜以及电导率测试等分析测试手段研究了均匀化热处理对Mg-5Zn-1Mn(ZM51)镁合金导电性能的影响。结果表明,铸态合金主要由α-Mg基体、Mg7Zn3相以及MgZn2相组成;经均匀化处理后,合金中Mg7Zn3相回溶,Mn原子从基体中析出,以单质形式存在;随着均匀化时间的延长,合金电导率从14.7 MS/m迅速升高至16.7 MS/m,最后趋于平稳。ZM51铸态合金经均匀化处理后的电导率上升归因于Mn原子的析出使合金基体晶格畸变降低抵消了由于Zn原子回溶造成合金电导率的降低。

The effects of homogenizing heat treatment on the electrical conductivity of ZM51 magnesium alloys were analyzed by optical microscopy,scanning electron microscopy and electrical conductivity tests.The results showed that the as-cast alloy mainly consists ofα-Mg matrix Mg7Zn3 phase and MgZn2 phase;after homogenization treatment,the Mg7Zn3 phase dissolved and Mn atoms were precipitated from the matrix and exist in elemental form;with the prolongation of homogenization time,the electrical conductivity increased rapidly from 14.7MS/m to 16.7MS/m and finally stabilized;the increase of conductivity of ZM51 alloy after homogenization was due to the decrease of the lattice distortion of the alloy matrix due to the precipitation of Mn atoms,which offseted the decrease of the alloy conductivity due to the back dissolution of Zn atoms.