Ca对原位自生Mg_2Si/ZM5复合材料组织与性能的影响

Influence of Ca addition on microstructure and mechanical properties of in-situ Mg_2Si/ZM5 magnesium matrix composite

通过真空感应炉中氩气保护,在ZM5熔体中加入Si获得原位反应自生Mg2Si/ZM5复合材料.采用金相显微镜、环境扫描电镜、拉伸实验等研究了Ca对该材料组织与性能的影响规律.结果表明:Ca的加入改变了Mg2Si/ZM5复合材料中Mg2Si相的形貌,使其从不规则的汉字状变成较细小的多角形,从而改善了材料的力学性能;当加入0.05%Ca(质量分数)时,复合材料的室温力学性能最好,屈服强度提高了10.4%,延伸率提高了52.4%;在200℃高温下,当含Ca0.05%～0.10%(质量分数)时其屈服强度和延伸率最好,分别提高了30.1%和92.3%.

The in-situ Mg_2Si/ZM5 magnesium matrix composite was fabricated by adding Si into the molten ZM5 magnesium alloy under argon atmosphere in vacuum induction furnace. The effects of Ca on microstructure and mechanical properties of in-situ Mg_2Si/ZM5 magnesium matrix composite were investigated by opitical microscope, environmental scanning electron microscope, tensile test machine, etc. It is found that with the increasing Ca addition in composites, Mg_2Si is transformed from a irregular Chinese script morphology to fine granular morphology, thus improving the mechanical properties of the material. When Ca addition is about 0.05%(mass fraction), excellent properties can be obtained, i.e., the increase of yield strength and elongation of the material is (about) 10.4% and 52.4%, respectively. At 200℃, when Ca addition is about 0.05%0.10%(mass fraction), the yield strength and elongation of the material can reach the highest values, the extent of increase is about 52.4% and 92.3%, respectively.