Mechanical Properties of Al<sub>2</sub>O<sub>3</sub>-TiN Nanocomposite Ceramic Tool Materials

Abstract

Al2O3-TiN nanocomposite ceramic tool materials were fabricated by hot-pressing technique and the mechanical properties were measured. Mechanical properties such as room temperature flexural strength, Vickers hardness and fracture toughness were measured through three-point bending test and Vickers indentation. The effects of the content of nano-scale TiN, sintering temperature and holding time on the mechanical properties were investigated. The results shows that the addition of nano-scale TiN can improve the mechanical properties of alumina ceramics. Both the flexural strength and the fracture toughness first increased then decreased with an increment in the content of nano-scale TiN. Both the Vickers hardness and the fracture toughness increased with an increment in the sintering temperature. The flexural strength increased with an increment in the holding time, while the fracture toughness decreased with an increment in the holding time. The composites with only nano-scale TiN have the highest Vickers hardness for the holding time of 30min, while the hardness of the composites with nano-scale TiN and micro-scale TiN decreased with an increment in the holding time.