Mechanical and tribological properties of TiB2-Ti composites prepared by spark plasma sintering

Abstract

The TiB2-Ti composites with different concentrations of the Ti metallic second phase were prepared by the spark plasma sintering. We investigated the tribological properties of TiB2 and TiB2-Ti materials by ball-on-disc technique on the HTT CSM tribometer under loads of 1, 5, and 10 N. The wear tracks morphology was investigated by scanning electron and confocal microscopy. The microstructures of the TiB2 + Ti materials consist of a small-grained matrix with relatively well dispersed TiB2 particulate grains. The wear test results show that the wear rate of composites is gradually reduced over the sliding speed range for all normal loads. The composite wear rates are lower than the monolith ones. The Ti phase played a dual role in improving the tribological properties of the TiB2-Ti composites by acting as a lubricant and in increasing the fracture toughness by influencing the microstructure and mechanical properties.