Dynamic fracture behavior of a MAX phase Ti3SiC2

Due to their layered structure, MAX phase ternary carbides and nitrides exhibit unique mechanical properties between their metal and ceramic constituent materials. Pre-cracked coupons of MAX phase Ti3SiC2 were impacted at 4 m/s, and high-speed imaging, combined with digital image correlation (DIC), captured full-field displacement data during loading and subsequent fracture. An over-deterministic least squares analysis was used to extract dynamic anisotropic mixed-mode stress intensity factors (SIFs). Critical Mode I (opening) SIFs at initiation are comparable to quasi-static fracture values in the literature averaging 6.9 MPa m1/2, but SIFs increase 20% during propagation, with increased crack tip sliding behavior influenced by inherent mesoscale toughening mechanisms.