镁合金AZ91HP表面激光重熔Al_2O_3涂层的组织及性能  

MICROSTRUCTURE AND PROPERTIES OF LASER REMELTED Al_2O_3 COATING ON MAGNESIUM ALLOY AZ91HP SURFACE

作　　者：王存山[1] 高亚丽[1] 姚曼[2] 

机构地区：[1]大连理工大学三束材料改性国家重点实验室,大连116023 [2]大连理工大学材料科学与工程学院,大连116023

出　　处：《金属学报》2007年第5期493-497,共5页Acta Metallurgica Sinica

基　　金：大连理工大学青年教师培养基金资助项目

摘　　要：采用等离子喷涂和激光重熔复合工艺在AZ91HP镁合金表面制备了Al2O3陶瓷涂层．结果表明,由于受激光作用区温度场分布、陶瓷材料热物性参数和涂层厚度等因素的综合影响,激光重熔Al2O3涂层呈现出明显的分层结构特征．依据组织结构不同,可将其分为:由α-Al2O3柱状晶构成的表面熔凝区、具有团絮状形貌特征的烧结区以及保持原喷涂态结构特征的残留等离子喷涂层．由于激光重熔陶瓷涂层表面单相α-Al2O3柱状晶的形成,使其硬度及耐磨、耐蚀性均明显优于等离子喷涂Al2O3涂层和原始镁合金．Al2O3 ceramic coating prepared by plasma spraying on AZ91HP Mg alloy was remelted by laser. The results show the remelted coating exhibited obvious layer-like characteristic due to influence of temperature distribution, thermophysical parameters and coating thickness. According to the microstructural difference, the coating can be divided into the remelted zone composed of the α-Al2O3 columnar crystals, the sintered zone with flock-like structure, the residual plasma-sprayed zone. Because of the formation of column-like crystals, the hardness, wear and corrosion resistances of the laser remelted coating are much higher than those of the plasma-sprayed coating and as-received magnesium alloy.

关 键 词：AZ91HP镁合金 AL2O3陶瓷涂层 等离子喷涂 激光重熔 

分 类 号：TG114[金属学及工艺—物理冶金] TG113.1[金属学及工艺—金属学]