Effects of the Carbon Content on the Properties of WC–TiC–Co Alloys

The effects of the binder composition in the cemented carbides have been investigated, and it is known that the binder composition or the carbon content of the alloys has a remarkable effect on the properties of the two-phase WC–Co alloys. However, no research has so far been carried out on WC–TiC–Co alloys.In the present experiment, ordinary WC–TiC–10% Co alloys which contain 6∼25% titanium carbide in carbides and consist of (WC+β+γ) three phases were vacuum-sintered. The carbon contents of the specimens were strictly controlled. The relation between the properties of the sintered alloys and the carbon content or the titanium carbide content was examined. The results obtained were as follows: (1) The lattice parameters of the γ and β phases showed a regular change in the three-phase region due to the change in composition in both phases. (2) The tungsten content in the binder phase of the three phase alloys varied from 2∼3% in minimum to 9∼10% in maximum depending on the carbon content. The amount of tangsten dissolved in the binder phase corresponded to the values in the WC–Co alloys. (3) The addition of titanium carbide resulted in an extreme extension of the three phase range owing to the change in carbon content in the β phase. (4) The properties, such as transverse-rupture strength, magnetic saturation, etc., varied regularly within the three-phase region.