轴向送粉等离子喷涂制备TiB_2/Al_2O_3复合陶瓷涂层

TiB_2/Al_2O_3 COMPOSITE COATING PREPARED BY THE AXIAL PLASMA SPRAYING

将Al2O3-30%(质量分数,下同)TiB2的复合粉与10%粒度为80～200nm的Al2O3粉混合,喷雾干燥造粒制备成热喷涂喂料,采用三阴极轴向送粉等离子喷涂系统(Axial-Ⅲ)喷涂沉积TiB2/Al2O2涂层。用X射线衍射、扫描电子显微镜及能谱仪分析涂层物相组成、微观形貌,测试涂层表面显微硬度和Rockwell硬度。结果表明:涂层由α-Al2O3,γ-Al2O3,TiB2和少量TiO2组成;TiB2在涂层中主要以颗粒状形态存在。显微硬度为16.68GPa;涂层表面Rockwell硬度平均值达52.9。

Sprayable feedstocks were prepared by spray-drying and using alumina-30% titanium diboride composite powder mixed with 10% nanoscale alumina powder with a particle size of 80-200nm, and a titanium diboride-alumina composite coating was deposited by axial-Ⅲ plasma spraying system. The coating constitution and microstructure were analyzed by X-ray diffraction, scanning electron microcopy. Microhardness and Rockwell Hardness were tested on the surface of the coating. Results show that the coat- ing consists of α-alumina, γ-alumina, titanium diboride and a small amount of titania; titanium diboride is mostly presented with particles in the coatings. The average superficial Rockwell hardness of as-sprayed coating is 52.9, microhardness of TiB2 is 16.68 GPa.