Effect of SiC and ZrO2 on sinterability and mechanical properties of titanium nitride, titanium carbonitride and titanium diboride

ZrO2 and SiC addition were effective in improving sinterability and mechanical properties of TiB2. This effect was applied to TiN and Ti(C-30,N-70) in this research to clarify the mechanism of the effect. ZrO2 addition improved the sinterability of TiN and Ti(C-30,N-70), however, SiC addition retarded the densification, different from TiB2. Both ZrO2 (20%) and SiC (2.5%) addition was required to obtain compacts having three point bending strength of 1200MPa by sintering and hot isostatic pressing. Si was detected in ZrO2 grains and grain boundaries in TiN-19.5%ZrO2-2.5%SiC by TEM-EDS. SiC addition made tetragonal phase of ZrO2 more stable and resulted in obtaining high strength.