Tungsten Carbide Cutting Tool Wear Mechanism

In the initial stage of tungsten carbide tool wear, plastic deformation of Co binder phase in the surface layer is extruded Co WC grains. Due to the small Co hardness, good ductility, under certain conditions, may be in surface friction micron film formation, while a hard WC particles are slowly protruding from the friction surface, to avoid the rapid wear of the surface and further, the procedure proceeds to friction relatively stable phase. With the loss of binder phase of Co, WC skeleton material destruction, a significant increase in the dislocation density WC particles, when the dislocation density is accumulated to a certain amount, it will form a micro-cracks in the WC particles, and thus make WC carbide particles begin to pull out from the matrix. Shedding of WC particles remain in the wear area into abrasive, under load extrusion occurs and the substrate, resulting in plastic deformation and breakage of new grains.