相組成及界面
(湖南大學 材料科學與工程學院，長沙 410082)
摘 要: 采用雙輥霧化法制備快速凝固AZ91鎂合金粉末，并用粉末冶金方法制備SiC顆粒增強的鎂基復合材料棒材，研究AZ91/SiCp復合材料的微觀組織、相組成及增強相與合金基體間的界面結(jié)構(gòu)特點。結(jié)果表明：雙輥霧化快速凝固AZ91鎂合金粉末的相組成為α-Mg固溶體主相和微量細小的T-AlMg2Zn相，尺寸在0.2 m左右；在后續(xù)熱擠壓過程中合金基體中析出大量的球形-Mg17Al12，尺寸在0.5 m左右，而T-AlMg2Zn相的形貌和尺寸無明顯變化；復合材料在加熱過程中，增強相SiC顆粒表面的SiO2層與合金基體之間發(fā)生界面反應。
關(guān)鍵字: 鎂基復合材料；快速凝固；粉末冶金；界面
metallurgy AZ91/SiCp Mg-based composite material
（College of Materials Science and Engineering, Hunan University, Changsha 410082, China）
Abstract:Rapidly solidified (RS) AZ91 magnesium alloy powders and the Mg-based composite material reinforced by SiC particles were produced by twin-roller atomization method and powder metallurgy, respectively. The microstructure, phase compositions and interface characterization between Mg matrix and reinforcing particles of AZ91/SiCp composite material were investigated. The results show that the RS AZ91 magnesium alloy powders are composed of α-Mg and a small quantity of fine T-AlMg2Zn with grain size of about 0.2 μm. A large number of global β-Mg17Al12 with grain size of about 0.5 μm are observed after hot extrusion, but the appearance and grain size of T-AlMg2Zn phase is not changed remarkably during hot extrusion. In the heating process of the composite material, the interface reaction occurs between the layers of SiO2 on the surface of SiC particles and Mg matrix.
Key words: Mg-based composite material; rapidly solidified; powder metallurgy; interface
