Ti-C-Al复合涂层与镁合金基体连接界面微观结构研究

Research on Microstructure of Connection Interface Between Al_2O_3/TiC Corrosion Resistant Coating and Mg Alloy Matrix

通过LWY400P激光器,用激光熔覆的方法在镁合金表面熔覆一层Ti-C-Al复合陶瓷涂层。原料中钛碳原子比为1∶1,铝含量10%~40%（质量分数）。分别用扫描电镜和能谱分析仪对熔覆层的微观组织、显微形貌和成分分布进行了测定和分析。结果表明,激光熔覆Ti-C-Al复合涂层是典型的快速凝固组织,涂层组织致密,晶粒细小。原料中Al含量对熔覆效果影响很大,Al含量越高,试样致密度越好,通过试验确定了原料中Al的最佳用量。融合区域各元素相互扩散,涂层与基体发生互熔,形成冶金结合,达到强化目的。

Abstract ：Ti-C-Al composite ceramic coating was prepared by laser cladding on Mg alloy surface with a LWY400P laser. The ratio of titanium and carbon atom in material is 1：1, and the aluminum content ranges from 10% to 40% （mass fraction）. Cross-section microstructure characteristics and chemical compostion distribution of the coating were studied by using SEM and EDS. The results show that, the laser cladding coating is typical rapid solidification structure; the coating is dense and grain is fine. The AI content in material has great influence on cladding, the density of the specimen gets higher with the Al content increasing. The best amount of Al in raw material has been identified by experiment. Elements in melting area diffuse each other, and coating and substrate melt together, which forms a metallurgical bond, and achieves the goal of hardening surface.