Effect of bimodal WC particle size and binder composition on the morphology of WC grains in WC–Co–Ni3Al cemented carbides

Yingbiao Peng, Tao Li, Jianzhan Long, Haohan Li, Bizhi Lu, Fei Chen, Yong Du
2021 Journal of Materials Research and Technology  
Grain growth WC morphology 2D nucleation CoeNieAl binder a b s t r a c t In addition to dispersed nanoparticles in the binder phase, the effect of Ni 3 Al on the growth mechanism of tungsten carbide (WC) grains is also essential for the fabrication of highquality of cemented carbides. In this work, WCeCoeNi 3 Al cemented carbides with different combinations of Co and Ni 3 Al binders was studied by using the original artificial bimodal WC grain size distribution. The WC particle sizes of medium
more » ... mm, fine 1 mm and ultrafine 0.2 mm were adopted. A series of WCeCoeNi 3 Al alloys were firstly designed based on thermodynamic calculations and then liquid-sintered at 1450 C for 1 h. Subsequently, the morphology and grain size distribution of WC grains were studied. By increasing the proportion of Ni 3 Al in the CoeNi 3 Al composite binder phase, the solideliquid interfacial energy increases significantly, which may provide a higher driving force for abnormal grain growth (AGG) through 2-dimension (2D) nucleation. However, the increase of Ni 3 Al proportion conversely greatly raises the energy barrier for the migration of W and C atoms into liquid binder phase, which finally retards the AGG of WC. Consequently, the AGG of WC decreases and the number of crystallites with blunt faces increases on WC particles with the increase of Ni 3 Al proportion, which can be well accounted for by the presently detected WC morphology evolution.
doi:10.1016/j.jmrt.2021.03.077 fatcat:2wh4jethczb5fay632sd7izmye