Elastic properties of Ta4AlC3 studied by first-principles calculations

Elastic properties of Ta4AlC3 were studied by first-principles calculations. The five independent elastic constants were derived yielding c11=437GPa, c12=158GPa, c13=197GPa, c33=416GPa, c44=165GPa. The bulk modulus BB, Young’s modulus EE, shear modulus GG, and Poisson’s ratio vv were determined to be 266 GPa, 362 GPa, 142 GPa, and 0.27, respectively. Ta4AlC3 is elastically stable with a Ti4AlN3-like structure. Ta4AlC3 exhibits largely isotropic properties in compression and is slightly anisotropic in shear. The in-plane elastic anisotropy in a–ca–c plane of Ta4AlC3 was also revealed.