Damage mechanisms of Ti3AlC2 ceramics in pulsed laser processing

Abstract

The damage mechanisms of Ti3AlC2 ceramics during laser processing in air and water were studied using the pulsed laser. The focused high-energy laser induced the melting of surface of Ti3AlC2 ceramics, causing the decomposition of Ti3AlC2 into TiC and Al with Al rapidly evaporating. During the laser processing in the air, oxygen diffused inward to form a solid solution of TiCxOy, and the rapidly heating and cooling of resolidified layer generated high thermal tensile stresses to result in a large amount of microcracks. When processing in the water, the thermal stresses were greatly weakened, and the outward diffusion of Al steam resulted in the voids on the sample surface. Additionally, it is determined that after treating in the air and water, the residual flexural strengths of Ti3AlC2 ceramics could retain the high values of 292 MPa and 484 MPa, and the Weibull moduli were kept at 7.2 and 16.0, respectively, exhibiting the excellent damage tolerance and high reliability.