Effects of TiN addition on the properties of hot pressed TiN-Ti/Al2O3 composites

TiN-Ti/Al2O3 composites of varying TiN content (0-20 vol%) were prepared by vacuum hot-pressing sintering at different temperatures (1400 °C and 1500 °C) to investigate how TiN affected the mechanical properties and electrical conductivity of the composites. Sintered samples with added TiN exhibited better performance than those without it. The sample with 20 vol% TiN sintered 1500 °C had an optimal relative density of 99.49, Vickers hardness of 14.94 GPa, flexural strength of 321.55 MPa, and electrical resistivity of 1474.7 μΩ cm. However, this increased temperature did not improve the best sample resistivity of 930.3 μΩ cm, which was obtained at 1400 °C. Form SEM images and XRD patterns, the positive effect of TiN on composite mechanical properties may be ascribed to its good performance of high hardness and strength, a decrease of the brittle intermetallic phase, the form of AlTi3N, and the impact of the fine-grained strength of the TiN phase.