表面纳米化对AZ91D镁合金渗铝行为的影响  

Influence of Surface Nanocrystallization on Aluminizing Behavior of AZ91D Magnesium Alloy

作　　者：张聪惠[1,2] 宋国栋 王婧 赵旭[1] Zhang Conghui;Song Guodong;Wang Jing;Zhao Xu(Xi'an University of Architecture and Technology,Xi'an 710055,China;Shaanxi Metallurgical Engineering Technology Research Center,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学,陕西西安710055 [2]陕西省冶金工程技术研究中心,陕西西安710055

出　　处：《稀有金属材料与工程》2020年第2期447-453,共7页Rare Metal Materials and Engineering

基　　金：Key Projects of Science and Technology Research of the Ministry of Education(211178);Yulin Municipal Science and Technology Bureau Project(2014cxy-05)。

摘　　要：镁合金表面渗铝是提高耐蚀性的一种有效方法。本研究将表面纳米化作为渗铝的预处理过程。采用高能喷丸对AZ91D镁合金进行表面纳米化处理,然后进行真空铝扩散得到渗铝层。用透射电镜(TEM)和扫描电镜(SEM)观察了渗铝层的形貌。结果表明,在对AZ91D镁合金表面高能喷丸后获得了100 nm的晶粒尺寸。在高能喷丸之后,渗铝层的深度比未高能喷丸的渗铝层厚。在440℃下扩散12 h后,渗铝层的深度增加到70μm。采用电化学方法对AZ91D镁合金的耐腐蚀性能进行了表征。结果表明,渗铝层明显降低了AZ91D镁合金的腐蚀速率。因此,高能喷丸强化有利于镁合金表面渗铝,提高镁合金的耐蚀性。Surface aluminizing for magnesium alloy is an effective method to improve corrosion resistance.This research introduced surface nanocrystallization as the pre-process of aluminizing.AZ91D magnesium alloy was processed by high energy shot peening(HESP) to achieve surface nanocrystallization,and then vacuum solid state aluminum diffusion was performed to obtain aluminized layer.The morphology of the aluminized layer was observed by transmission electron microscopy(TEM) and scanning electron microscopy(SEM).The results show that the surface of the nanocrystalline with grain size of 100 nm is obtained after HESP of AZ91D magnesium alloy.The depth of the HESPed aluminized layer is thicker than that of the aluminized layer without HESP.After 440℃/12 h diffusion,the depth of aluminized layer increases to 70μm.The corrosion resistance of AZ91D magnesium alloys were characterized by electrochemical method.It is shown that the aluminized layer obviously lowers the corrosion rate of AZ91D magnesium alloy.Therefore,high energy shot peening(HESP) is beneficial to surface aluminizing and can improve the corrosion resistance of magnesium alloy.

关 键 词：高能喷丸 表面纳米化 铝扩散 耐腐蚀性 

分 类 号：TG174.445[金属学及工艺—金属表面处理]