(1. 北京理工大学 材料科学与工程学院, 北京100081;
2. 北京航空航天大学 材料科学与工程学院, 北京100083)
摘 要:
关键字: AZ31镁合金;过共晶渗层;耐蚀性;纳米硬度
coating on AZ31 magnesium alloy
(1. School of Materials Science and Engineering, Beijing Institute of Technology,
Beijing 100081, China;
2. School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics,
Beijing 100083,China)
Abstract:Liquid diffusion technology was used to aluminize on the surface of AZ31 magnesium alloy. The hypereutectic aluminized coating was obtained. The forming mechanism and properties of aluminized coating were studied by analyzing the component, phase state, nanoindentation hardness and corrosion resistance. The results show that a solidification-melting process occurs on the surface of AZ31 magnesium alloy when it is aluminized at 480 ℃. Mg17Al12 and Mg-Al supersaturated solid solution exist in the aluminized coating, and the coating nanoindentation hardness is about 3 times higher than that of AZ31 magnesium matrix, at the same time the corrosion resistance is improved obviously. Aluminizing in liquid phase may improve the diffusion velocity but up-and-down surface is formed due to surface solidification shrinkage from liquid phase, which can be controlled by reducing the cooling velocity.
Key words: AZ31 magnesium alloy; hypereutectic coating; corrosion resistance; nanoindentation hardness