汽车发动机用AZ91合金的激光表面改性处理  

Laser surface modification of AZ91 alloy for automobile engine

作　　者：胡新林[1] 钱鸣[2] 

机构地区：[1]安徽机电职业技术学院汽车工程系,安徽芜湖241000 [2]北京工业大学激光工程研究院,北京100124

出　　处：《金属热处理》2016年第4期170-174,共5页Heat Treatment of Metals

基　　金：国家科技支撑计划(2011BAF11B06)

摘　　要：采用预置式两步激光熔覆的方法在汽车发动机用AZ91合金表面进行了等离子喷涂+激光熔覆改性处理,通过金相、扫描电镜、XRD、硬度和极化曲线等测试手段,研究了激光熔覆Al-Si层的显微组织和耐腐蚀性能。结果表明,激光熔覆层主要由α-Al和(α-Al+β-Si)共晶组织组成;激光熔覆层的显微硬度要高于等离子喷涂层,且两种涂层的显微硬度都要高于基体合金;改性层和基体合金的耐腐蚀性能从高至低依次为:激光熔覆层>等离子喷涂层>AZ91合金。The surface of AZ91 alloy for automobile engine was modified by plasma spraying and laser cladding treatment,the microstructure and corrosion resistance of laser cladding Al-Si layer were studied by means of metallographic,scanning electron microscope,XRD,hardness and polarization curve test. The results show that the laser cladding layer is mainly composed of α-Al and（ α-Al ＋ β-Si） eutectic structure;the microhardness of laser cladding layer is higher than that of plasma spraying coating,and the microhardness of the two kinds of coatings are higher than that of matrix alloy; the corrosion resistance from high to low order is laser cladding coating,plasma spraying coating and AZ91 alloy.

关 键 词：AZ91合金 激光熔覆 硬度 腐蚀 

分 类 号：TG124.2[金属学及工艺—金属学]