The WC/Co is one of broad class of cermet materials (CM) that are applied in fabrication of machining tools. It means that they are subjected to different kind of dynamic loadings. They have very good mechanical properties. However, the degradation of the CM material under dynamic load has not been enough thoroughly investigated. Experimental results yield that the dissipation of the fracture energy in WC/Co samples is due to Co ductile failure at the WC and Co interface [1] and/or dimple rupture mechanism [2]. Stress concentrations about stress raisers such as grain bounds cause microcracking that is further propagated by dynamic loading. However, there are no such predictions for impact conditions. The main goals of the presentation are to explore the formerly created models of the two-phase composite [3, 4] towards impact conditions impacts and give qualitative predictions of the crack and plastic strains initiation for such cases. It has been found that microcracks development process and stress fields depend on impact velocity and the existence of discontinuities: (1) inside the Co binder and (2) the interface between the binder and the grains. Estimation of the microcracks distribution by means of damage parameter is given.
展开▼
