Mechanical properties of bulk sintered titanium nitride ceramics

Titanium nitride is well used for improving wear and corrosion resistances of various mechanical parts, cutting tools (tips), dies, or in decorating watch case or table wears by means of coating techniques, such as chemical vapor deposition process or physical deposition process. These uses are limited to thin films of titanium nitride of thickness less than 10 μm. Few studies have been reported on synthesis of bulk TiN samples (abbreviated as bulk TiN in the following). The purpose of the present study is to synthesize bulk TiN ceramic and to estimate its mechanical properties. Synthesis of bulk TiN ceramic is tried by hot-press with DC pulsed directly heating TiN powder under the following conditions: Sintering temperature range: 1723-2023 K. sintering time: 60 s-1.5 ks, sintering pressure: 16.63-62.39 MPa. Observation of the microstructure of these bulk TiN using a scanning electron microscope, measurement of mechanical properties of bulk TiN using an Acoustic Spectro Microscopy method, indentation fracture toughness technique, and density by Archimedes' method were carried out. Bulk TiN ceramic of which size is 30 mm in diameter and about 30 mm in height were successfully synthesized under all conditions in the present study. The maximum relative density was obtained to about 97%, the maximum Young's modulus to 430 GPa, the highest Vickers hardness to 2012, respectively. This bulk TiN might be a new candidate as mechanical components, which requires high wear resistance.