Sintering behavior of WC-10Co-V(C, N) nanocrystalline gradient cemented carbide

In the present study, nanocrystalline gradient cemented carbide with an average grain size of only 155 nm in tungsten carbide (WC) was prepared using V(C, N), and its sintering behavior was investigated. Scanning electron microscopy (SEM) and electro probe micro-analysis (EPMA) revealed that V(C, N) promotes the formation of a cubic carbide free layer (CCFL) and effectively suppresses the WC grains in the nanocrystal range at different sintering temperatures and holding times compared with Ti(C, N). The gradient cemented carbide had the highest hardness (2169 kg/mm2), the highest fracture toughness (11.94 MPa/m2), and the lowest friction coefficient (0.22) and wear resistance when the sintering temperature was 1400 degrees C and the holding time was 60 min. In addition, the cobalt (Co)-poor phenomenon occurred in the CCFL of the gradient cemented carbide, which was mainly related to the small radius of the capillaries in the nanocrystals.

Automated summary

In this study, nanocrystalline gradient cemented carbide with a grain size of 155 nm was successfully prepared using V(C, N) and its sintering behavior was investigated. V(C, N) was found to promote the formation of CCFL and suppress the growth of WC grains at different sintering temperatures and holding times. The gradient cemented carbide exhibited superior hardness, fracture toughness, friction coefficient, and wear resistance at a sintering temperature of 1400 degrees C and a holding time of 60 min. Additionally, the occurrence of Co-poor phenomenon in the CCFL was related to the small radius of capillaries in the nanocrystals.