添加 Mg 对 Al-Al2O3纳米复合材料力学性能和热电性能的影响

摘要

The effects of Mg addition on mechanical thermo-electrical properties of Al−Mg/5%Al2O3 nanocomposite with different Mg contents (0, 5%, 10% and 20%) produced by mechanical alloying were studied. Scanning electron microscopy analysis (SEM), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM) were used to characterize the produced powder. The results show that addition of Mg forms a predominant phase (Al−Mg solid solution). By increasing the mass fraction of Mg, the crystallite size decreases and the lattice strain increases which results from the atomic penetration of Mg atoms into the substitutional sites of Al lattice. The microhardness of the composite increases with the increase of the Mg content. The thermal and electrical conductivities increase linearly with the temperature increase in the inspected temperature range. Moreover, the thermal conductivity increases with the increase of Mg content.%采用机械合金化制备不同 Mg 含量(0，5%，10%，20%)的 Al−Mg/5%Al2O3纳米复合材料，研究 Mg 含量对材料力学和热电性能的影响。采用扫描电子显微镜、X 射线衍射和透射电子显微镜对所得粉末进行表征。结果表明，往 Al−Al2O3复合材料中添加 Mg 可形成 Al−Mg 固溶体。随着 Mg 含量的增加，Al 的点阵位置逐渐被 Mg取代，导致晶粒尺寸减小，晶格应变增加。随着 Mg 含量的增加，复合材料的显微硬度增加。热导率和电导率随着温度升高线性增加。热导率随 Mg 含量的增加而增加。