Identification of damage tolerance of Ti 3 SiC 2 by hardness indentations and single edge notched beam test

Abstract

The damage tolerance of Ti₃SiC₂ has been identified by Vickers indentations and single edge notched beam (SENB) testing. The Vickers indentations were made at loads of 0·5—30 kg to measure the hardness. The results showed that the hardness decreased with increasing loads. No indentation cracks were observed around the damage zones, even when the load applied was 30 kg. The material around microhardness indentations was pushed out, lots of grains were crushed into fragments under loads, and some grains exhibited lamination fracture. In addition, around the damage zones, a number of individual grains were delaminated and deformed heavily into a twisted shape. This suggests that Ti₃SiC₂ exhibits plasticity at room temperature. Moreover, the SENB test also suggested that this layered material is damage tolerant. The multi-absorbing energy mechanisms: grain pushout, pullout, and delamination, the buckling of individual grains, crack deflection, crack branching, and pinning, explained why the Ti₃SiC₂ is a damage tolerant material able to contain the extent of microdamage.