Anisotropic strength and plastic deformation behavior of MAX phase Ti3AlC2 under ultrahigh pressure

Machinable layered ternary carbides and nitrides (MAX phases) are a class of multifunctional materials combining the advantages of both ceramics and metals, making them of vital technological importance. Understanding their mechanical behavior is critical for practical applications and failure analysis. However, there is still no in situ investigation on their strength and plastic deformation under high pressure/stress. In this study, we investigate the strength and texture development of Ti3AlC2 under nonhydrostatic pressure up to 41 GPa. Clear strength anisotropy was observed and the lattice stress states of different planes were determined. At 41 GPa, the highest differential stresses supported by the (10-10) plane and (0008) plane are approximately 13.7 GPa and 4.5 GPa, respectively. The average strength exceeds that of stishovite, one of the strongest oxides. A strong 0001 deformation texture developed under ultra-high stress. This work clearly reveals the lattice-stress states and deformation behavior of Ti3AlC2 under high stress, offering direct experimental insights for the design and processing of MAX phase materials.