Influence of TiN particle dispersion on fracture resistance and contact damage of Si₃N₄ ceramics

Abstract

The fracture resistance curve and Hertzian contact fatigue test of TiN particle dispersed Si3N4 ceramics were carried out. The Si3N4 ceramics without TiN showed a typical R-curve, that is the KR was initially around 5.5 MPam1/2, it increased during fracture and it achieved 6.5MPam1/2 at the crack extension of 300m. On the other hand, Si3N4 ceramics with TiN particles has higher initial KR value and their R-curve indicated less slop than that without TiN. Although the strength of the Si3N4 ceramics without TiN degraded after cyclic indentation, that of TiN particle dispersed Si3N4 ceramics maintained because of limited crack generation and extension. The cyclic contact fatigue was explained by the difference in R-curve behavior.