Indentation hardness and fracture toughness in single crystal TiC0.96

Using the indentation technique, both the hardness and fracture toughness anisotropy of a titanium carbide single crystal have been investigated on the (001), (110) and (111) planes. The hardness values varied between 20 and 32 GPa, and the anisotropies were consistent with {{110}} 〈 1 1 ¯ 0 〉 slip. The indentation critical stress intensity factors KIa were in the range 1.5–3.6 MPam1/2. The anisotropy of KIa on (001) and (110) could be explained by a bond-breaking model but not that on (111). The experimental values were not consistent with the predicted ones.