激光熔覆AZ91D镁合金的界面特征和耐磨性研究  

Characterization and wear resistance of laser surface cladding AZ91D alloy

作　　者：林文光[1] 姚军[1] 

机构地区：[1]内蒙古工业大学材料科学与工程学院,内蒙古呼和浩特010051

出　　处：《轻合金加工技术》2008年第4期35-37,57,共4页Light Alloy Fabrication Technology

基　　金：内蒙古教育厅科研项目NJ04006

摘　　要：在AZ91D镁合金表面激光熔覆Al+Al2O3粉末制得复合涂层。用X-ray衍射确定激光熔覆层的相结构,用光学显微镜和扫描电子显微镜(SEM)观察激光熔覆层和AZ91D基体之间的结合区域的生长形态。结果显示,在激光熔覆层中Al2O3颗粒的分布是均匀的,结合区晶体的生长形态是一种独特的柱状树枝晶。温度梯度、树枝晶生长和熔池的凝固速度均影响它的形成。与AZ91D基体相比,激光熔覆层的耐磨性得到了改进。The laser surface cladding of AZ91D magnesium alloy with Al ＋ Al2O3 powders was investigated. X-ray diffraction （XRD） was used to identify the phases in the laser cladding layer, and the growth morphology of the boundary zone between the laser surface cladding layer and AZ91D substrate was observed by optical microscope and scanning electron microscope （SEM）. The ele- ments mapping scanning analysis on the boundary zone were carried out with energy-dispersive spectrum （EDS）. The results showed that the distribution of the Al2O3 particles was homogeneous in the laser surface cladding layer; the growth morphology of the bound-ary zone was found to be in a unique parallel-branching feature. The temperature gradient, the ultimate rate of dendrite growth, and the rate of pool solidification on the growing fronts affected its formation. Furthermore, compared with the AZ91D substrate, the wear resistance of the laser cladding coatings was improved.

关 键 词：镁合金 铝 生长形态 激光熔覆 耐磨性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]