Sintering Behaviour of Binderless Tungsten Carbide

Binderless tungsten carbide, a very hard and abrasion resistant material, has many interesting applications and attracts scientists and toolmakers alike. Hitherto, binderless tungsten carbide has been used to make wear parts, water jet nozzles or pressing tools for forming glass lenses. The sintering behaviour and the necessary sintering temperature are controlled by the carbide grain size as well as the nature and the amount of grain-growth inhibitors. In this work, the sintering behaviour of binderless tungsten carbide materials with different grain growth inhibitors and grain sizes between 100 nm and 600 nm was studied using dilatometry and thermal gravimetric analysis at temperatures up to 1950 °C. The densification mechanisms (solid and contributions of liquid state sintering) are dis cussed. Furthermore, the microstructure of dense sintered specimens in addition to their mechanical properties were studied and, together with the thermal analysis results, compared to conventional WC-Co hard metals.