Shear strength and shear failure of layered machinable Ti3AlC2 ceramics

Shear-induced failures in uniaxial compression and Hertzian contact damage of Ti3AlC2 fabricated by a solid–liquid reaction synthesis were investigated, and shear strength was evaluated using double notched samples and punch hole tests respectively. Compressive strength of 749 MPa and the slip angle of 38° between the slip plane and the loading direction were measured when the applied load was parallel to the hot-pressing direction of the material; whereas the compressive strength of 841 MPa and the angle of 26° were obtained when the applied load was perpendicular to the hot-pressing direction. The shear strength obtained using double-notched sample was 96 MPa and that from punch-shear test was 138 MPa, respectively. SEM fractographs of specimens failed in shear and compression tests indicated a combination of intergranular and transgranular fracture and also an evidence of friction in the slip plane during compression failure process. Punch-shear test was developed and confirmed to be a simple and feasible method for determining the shear strength of layered machinable ceramics.