激光重熔纳米SiC复合陶瓷涂层组织和性能研究

研究了WC／Co-NiCrAl等离子复合陶瓷涂层、激光重熔等离子涂层、激光渗入纳米SiC涂层的组织结构、耐磨性能。结果证明：在所定的工艺参数下，等离子喷涂层组织呈层片状，层间为机械结合界面；经激光重熔后，激光作用区涂层组织细化，孔隙率降低，耐磨性能是原等离子涂层的1．3倍；渗入纳米SiC后，组织进一步细化，孔隙率进一步降低，SiC颗粒仍处于纳米尺度，分布在粗颗粒表面及粗颗粒之间，其耐磨性能是原等离子涂层的2．6倍。

Research on Structures and Properties of Composite Ceramics Coatings by Laser Cladding Nano-SiC Powder

Three kind of WC/Co-NiCrAl composite ceramic coatings were formed by plasma spraying, laser cladding and laser cladding nanocrystalline SiC. The structures and wear resistance of the coatings were studied. The results show that structures of plasma sprayed coatings are lamella in shape, mechanical bond in interface regions. Laser cladding can cause the elimination of the lamella structural characteristics of plasma sprayed WC/Co-NiCrAl coatings and formation of the continuous and compact cladding coatings. After nanocrystalline SiC implants into plasma sprayed coatings by laser cladding, the structures of WC/Co-SiC composite ceramic coatings were finer and compacter than that of before implanting. At the same time, nanocrystalline SiC particles have no obvious growth and cover in coarse particles and bridges connection with coarse particles. With the wear tests, it is indicated that low laser power employed, the wear performance of the coatings without nano material increase to 1.3 times as that of the plasma coatings, at the same time, the wear performances of the coatings with nano material increase 2.6 times as that of the plasma spraying coatings.