Research Progress on the Effect of MgO Surface Film on Powder Metallurgical Mg Alloy

Author of the article:ZHANG Zhongming1,2, Wu Xiangquan1 , YANG Changlin2 , XU Chunjie1

Author's Workplace：1. School of Materials Science and Engineering, Xi'an University of Technology, Xi'an 710048, China; 2. State Key Laboratory of Solidification Processing; Northwestern Polytechnical University, Xi’an 710072, China

Key Words：magnesium alloy; powder metallurgy; oxide film

Abstract：Magnesium powders are easy to be oxidized, and the resultant surface oxide films hinder bonding of the powders, therefore the magnesium powder-metallurgy has to be conducted in vacuum or shielded gas atmosphere. Whereas, if the surface oxide film can be broken into fine submicron or even nanometer ultrafine particles by ball milling and severe plastic deformation, and evenly distributed in the process of powder metallurgy, it is possible to make the magnesium oxide particles become a dispersive enhancement phase and play a role in strengthening the magnesium alloy. The problems existing in the conventional powder metallurgy method for preparing magnesium alloys were analyzed, and the advantages of hot extrusion method for preparing high performance magnesium alloys were discussed. The effect of surface oxide film on powder metallurgy magnesium alloys was summarized, and the importance and necessity of reunderstanding the effect of surface oxide film on magnesium powder was pointed out.