纳米陶瓷微米高温合金复合涂层组织与性能

采用溶胶-凝胶化学包覆法制备纳米陶瓷微米高温合金复合粉末,用HVOF喷涂技术制备了复合涂层,采用SEM观察和摩擦磨损实验分析了复合粉末和复合涂层的组织和性能.研究表明:复合粉末是以纳米陶瓷为外壳包覆微米级高温合金颗粒核心的核壳式结构;陶瓷壳在喷涂过程中形成液相与高温合金液相熔合,烧结成致密陶瓷相,部分陶瓷在冷却过程中析出结晶体;复合涂层与基体的结合强度为59.2 MPa,摩擦系数为0.766,磨损率比纯高温合金涂层降低了32%.

Microstructure and properties of nano ceramic and micro super alloy composite coating

Nano ceramic and micro super alloy composite powders were prepared by sol-gel chemical coating method. Composite coating was fabricated by HVOF method fed with these composite powders. SEM observation and attrition test were used to analyze microstructures and properties of composite powder and composite coating. Experimental results show that characteristic of the composite powder is a core and shell structure composed of microsize super alloy powder coated by nanosize ceramic powder. Ceramic shells in composite coating sintered to dense ceramic and adhered to the alloy by forming a liquid phase in the process of spraying, and some ceramics crystallized in the process of cooling. Adhere strength and frication coefficient of composite coating is 59.2 MPa and 0. 766, respectively. Frication loss of composite coating decreased 32% comparing to pure super alloy coating.