Al2O3颗粒增强AZ91D镁基复合材料的研究

摘要

以平均颗粒尺寸为30nm的Al2O3颗粒作为增强相,采用全液态搅拌铸造法制备了Al2O3/AZ91D复合材料.通过光学显微分析、XRD衍射分析、SEM扫描和EDS能谱分析、硬度测试等检测手段对复合材料的显微组织和性能进行了研究.研究结果表明:由于初生相α-Mg在Al2O3颗粒表面非均质形核及Al2O3颗粒阻碍α-Mg相生长的双重作用使Al2O3/AZ91D复合材料的晶粒得到了明显细化,而且复合材料的硬度明显高于AZ91D合金,并随着Al2O3颗粒加入量的增加,其复合材料的硬度不断提高.%The Al2O3/AZg1D Mg matrix composite, Which is AZ91D Mg alloy reinforced by Al2O3 particulates with average sizes of 30nm, had been fabricated using the fluxless casting technique.The microscopic structure and performance of compound material has been studied by means of optical microscopic, XRD, SEM and EDS, hardness testing and so on.Experimental results showed that the Al2O3/AZ91D matrix grains were obviously refined by both heterogeneous nucleation of primary phase α-Mg on the surface of Al2O3 particles and prohibited growth of α-Mg phase.The Brinell hardness of Al2O3/AZ91D magnesium matrix composite was obviously higher than AZ91D alloys, and Brinell hardness of Al2O3/AZ91D magnesium matrix composite can be continuously enhanced with the increasing of addition of Al2O3 particles.