Forming process and microwave post-treatment of WC-12 Co cemented carbide cylindrical-shaped inner structure structure by selective laser melting

Firstly, different scanning strategies of SLM were used to prepare WC-12Co cemented carbide specimens, and the influence of scanning strategies on the formed specimens was investigated to optimize the best forming process. The optimized parameters were used to form the specimens with cylindrical-shaped inner structure and microwave post-treatment, to analyze the influence of microwave post-treatment process on the relative density, Vickers hardness and shape accuracy of the specimen. The results show that the most suitable for printing WC-12Co cemented carbide is the checkerboard scanning strategy, which is better than other scanning strategies in terms of forming ability, relative density, Vickers hardness and tissue uniformity. After adjusting the scanning spacing to 30 μm, the relative density of the specimen reaches the highest 91.6%, and the Vickers hardness is up to 1324 HV, and the checkerboard scanning strategy has a better precision of forming the cylindrical-shaped inner structure; when the microwave heat treatment heat treatment rate is 40 ℃/min, the temperature is 1300℃ and the holding time is 20 min, the number of microscopic defects of the specimen is greatly reduced compared with that before heat treatment, and the relative density, Vickers hardness of the material are significantly improved, but some of the WC grain sizes increase because of heat treatment, at this time, the relative density of the specimen reaches 96.1%, and the Vickers hardness reaches 1435 HV, and the precision of the specimen of cylindrical-shaped inner structure is not destroyed after the heat treatment.