Preparation and properties of supersonic atmospheric plasma sprayed TiB2-SiC coating
(1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Guangdong Key Laboratory of Modern Surface Engineering Technology, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangdong Institute of New Materials, Guangzhou 510650, China;
3. Yunnan Yunlv Yongxin Aluminum Company Limited, Honghe 661400, China)
2. Guangdong Key Laboratory of Modern Surface Engineering Technology, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangdong Institute of New Materials, Guangzhou 510650, China;
3. Yunnan Yunlv Yongxin Aluminum Company Limited, Honghe 661400, China)
Abstract: With the TiB2-SiC powders after spray granulation and vacuum calcination as raw materials, the TiB2-SiC coating was prepared by supersonic atmospheric plasma spraying (SAPS). The effects of spraying power and spraying distance on the properties of the TiB2-SiC coating were investigated and the fabrication processing of SAPS was optimized. The results show that the sprayed powders after calcination have a uniform particle size distribution, good sphericity and enhanced fluidity. The coating prepared by the calcined powders has a dense structure and high deposition efficiency. When the calcined TiB2-SiC powders are used and the spraying power is 95 kW and the spraying distance is 150 mm during supersonic plasma spraying, the obtained TiB2-SiC coating behaves the best comprehensive performance with the porosity, microhardness, bonding strength and resistivity equal to 5.6%, 3.57 GPa, 18.3 MPa and 10.8 mΩ·cm, respectively.
Key words: supersonic atmospheric plasma spraying (SAPS); TiB2-SiC coating; vacuum calcination; processing optimization