Abstract:A type of polymer-coated Al₂O₃/ZrO₂/TiC ceramic powder was prepared. The laser sintering mechanism of polymer-coated Al₂O₃/ZrO₂/TiC powder was investigated by studying the dynamic laser sintering process. It is found that the mechanism is viscous flow when the sintering temperature is between 80℃ and 120℃, and it is melting/solidification when the temperature is above 120℃. The process parameters of selective laser sintering were optimized by using ortho-design method. The results show that the optimal parameters include laser power of 14W, scanning velocity of 1400mm/s, preheating temperature of 50℃ and powder depth of 0.15mm. A two-step post-treatment process is adopted to improve the mechanical properties of laser sintered part, which includes polymer debinding and high temperature sintering. After vacuum sintering for 2h at 1650℃, the bending strength and fracture toughness of Al₂O₃/ZrO₂/TiC ceramic part reach 358MPa and 6.9MPa•m^1/2, respectively. 

Key words: selective laser sintering; polymer-coated Al₂O₃/ZrO₂/TiC ceramic