SHORT-TERM PROCESS OF RECYCLING CEMENTED CARBIDE SCRAPS AND PREPARATION OF HIGH PERFORMANCE HARD METALS
WANG Yao, LIU Xuemei, SONG Xiaoyan(), WEI Chongbin, WANG Haibin, WANG Xilong
Key Laboratory of Advanced Functional Materials, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124
Cite this article:
WANG Yao, LIU Xuemei, SONG Xiaoyan, WEI Chongbin, WANG Haibin, WANG Xilong. SHORT-TERM PROCESS OF RECYCLING CEMENTED CARBIDE SCRAPS AND PREPARATION OF HIGH PERFORMANCE HARD METALS. Acta Metall Sin, 2014, 50(5): 633-640.
Recycling of cemented carbide scraps is drawing more and more attention to companies and countries all over the world. However, the recycling method has always been a problem where there are many factors involved. The feasibility, recycling rate, energy consumption and the environment conservation are all significant factors for the recycling method that need to be considered. In this work, using the cemented carbides scraps as the raw material, the recycled WC-16%Co (mass fraction) composite powder was synthesized by oxidation, reduction and carbonization reactions. Then the recycled composite powder was sintered to prepare the hard metal bulks by sinter-HIP (hot isostatic pressing). The results indicate that with the carbon addition increases, the content of Co6W6C in the composite powders decreases while the total carbon and free carbon increase. When the carbon addition is 16.60%, the high-performance hard metal bulks can be obtained, with a fracture toughness of 23.05 MPa·m1/2 and a transverse rupture strength of 4020 MPa. Moreover, the Co phase distributes more homogeneously in the recycled hard metals. The larger mean free path of the Co phase and the lower contiguity degree of the WC grains lead to the high performance of the recycled hard metal materials.
Fund: National High Technology Research and Development Program of China (No.SS2013AA031401), National Natural Science Foundation of China (No.51174009),Natural Science Foundation of Beijing (Nos.2131001 and 2133062) and Fund of State Key Laboratory of New Metal Materials (No.2012-Z08)