Compressive Behavior of Ti3 AlC2 and Ti3 Al0.8 Sn0.2 C2 MAX Phases at Room Temperature.

In this study, we report on the compressive behavior of Ti₃ AlC₂ and Ti₃ Al_0.8 Sn_0.2 C₂ MAX phases at room temperature. We found that these two phases could be classified as Kinking Nonlinear Elastic (KNE) solids. The cyclic compressive stress-strain loops for Ti₃ AlC₂ and Ti₃ Al_0.8 Sn_0.2 C₂ are typical hysteretic and fully reversible. At failure, both compositions fracture in shear with maximum stresses of 545 MPa for Ti₃ AlC₂ and 839 MPa for Ti₃ Al_0.8 Sn_0.2 C₂. Consequently, the macroshear stresses for failure, τ_c, are 185 MPa and 242 MPa for Ti₃ AlC₂ and Ti₃ Al_0.8 Sn_0.2 C₂, respectively. In addition to the grain size effects, the presence of a ductile Ti _x Al _y intermetallic distributed in the grain boundaries plays an important role in the enhancement of the ultimate compressive and macroshear stresses for Ti₃ Al_0.8 Sn_0.2 C₂. SEM observations reveal that these two MAX phases exhibit crack deflections, intragranular fractures, kink band formation and delaminations, grain push-in and pull-out. [ABSTRACT FROM AUTHOR]