Combination of cryogenic and pulsed electric field treatment for enhanced microstructure and mechanical properties of WC–Co cemented carbides
Mingchao Ma, Shanshan Hu, Yingchun Diao, Kai Wang, Guojian Li, Wangzhong Mu, Qiang Wang
Abstract
Abstract In this work, we aim to develop a novel post‐treatment process combining cryogenic and pulsed electric field treatment to enhance WC–Co cemented carbides. The results show a 15.62% increase in hardness from 1831.38 to 2117.38 HV 30 , a 9.60% rise in fracture toughness from 9.06 to 9.93 MPa·m 1/2 , while the friction coefficient decreases from 0.63 to 0.47. Through the residual stress evolution, WC orientation change and the martensitic transformation of Co, and the internal enhancement mechanism of cryogenic combined with pulsed electric field treatment are revealed. The electron wind generated by the pulsed electric field can efficiently reduce the residual stress induced by cryogenic process. The evolution of residual stress promotes the base slip of WC, increasing the degree of {0001} orientation. In addition, the degree of martensitic transformation of Co intensifies, with the hcp‐Co/fcc‐Co ratio rising from 0.41% to 17.86%. The enhanced WC {0001} orientation and increased hcp‐Co content contribute to significant improvements in hardness and wear resistance. This work provides a novel efficient enhancement strategy for ceramics and alloys, with the potential to be a mainstream strengthening method in the future.