Thermal Stability and Coefficient of Friction of the Diamond Composites with the Titanium Compound Bonding Phase

In this paper, processes occurring during heat treatment of the diamond-Ti compound composites without Co addition were investigated and compared with commercial PCD. Three types of materials were prepared. The first material was sintered using the mixture containing diamond and 10 mass% of TiC, the second material was prepared using diamond powder and 10 mass% of Ti-Si-C, and the third composite was sintered using the addition of 10 mass% of TiB2. During the research, it was proved that TiO2 formation contributes to material swelling and WO3 (W is present from the milling process) causes a significant increase in coefficient of friction. TiC and Ti-Si-C bonded materials are very susceptible to this process of oxidation; their hardness drops absolutely after wear test at 600 °C. The diamond composite with TiB2 is the most resistant to oxidation from investigated materials.