(1. 南京航空航天大学 机电学院，南京 210016；
2. 中国科学院 上海光学精密机械研究所，上海 201800；
3. 南京先进激光技术研究院，南京 210038)
摘 要: 以纳米团聚体Al2O3-13%TiO2(质量分数)复合涂层粉末为原材料，采用激光熔覆工艺在Ni625合金基体表面制备316L微孔结构/Al2O3-13%TiO2复合涂层。通过扫描电镜(SEM)、XRD和线扫描仪分析涂层和微孔粘结层的界面形貌和界面元素的分布状态，研究微孔结构对涂层结合强度的影响。结果表明：界面间结合方式为机械结合；虽然界面之间未发生元素扩散现象，但在微孔粘结层“铆接”作用下，粘结层与陶瓷层间形成良好的结合，与直接激光熔覆Al2O3-13%TiO2涂层相比，316L微孔结构/Al2O3-13%TiO2复合涂层结合强度较高，提高8.7%；残余应力相对较低，减小13.6%，且表面涂层由α-A12O3、Rutile-TiO2和Al2Ti7O15组成，其中以稳态的α-A12O3相为主要组成相。
关键字: Al2O3-13%TiO2；微孔粘结层；残余应力；激光熔覆；结合强度
（1. Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
2. Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China;
3. Nanjing Institute of Advanced Laser Technology, Nanjing 210038, China）
Abstract:The nano-agglomerates (Al2O3-13%TiO2) powders were used as the raw material to prepare the 316L micro-porous structure/Al2O3-13%TiO2 composite coating on the surface of Ni625 alloy by laser cladding. The morphology and element distribution of interface between coating and micro-porous layer were analyzed by SEM, XRD and line scanner. The effect of micro-porous structure on bonding strength of the coating was studied. The results show that the combination between the bonding layer and the ceramic layer is the mechanical. The bonding layer is well combined with the ceramic layer under the function of “riveting” of the micro-porous bonding layer, although there is no element diffusion between the interface. Compared with the direct laser cladding Al2O3-13%TiO2 coating on the surface of Ni625 alloy, the bonding strength of the 316L micro-porous/Al2O3-13%TiO2 composite coating is higher, which is increased by 8.7% and the residual stress is lower, which is reduced by 13.6%. The surface coating is composed of α-A12O3, rutile-TiO2 and Al2Ti7O15.The main phase is α-A12O3.
Key words: Al2O3-13%TiO2; micro-porous bonding layer; residual stress; laser cladding; bonding strength
