Elastic constants of polycrystalline Ti₃AlC₂ and Ti₃SiC₂ measured using coherent inelastic neutron scattering

Abstract

The magnitude of the single‐crystal elastic constant c44 in the MAX phase Ti3SiC2 is under debate. In this paper, estimates for the magnitude of c44 for MAX phases Ti3AlC2 and Ti3SiC2 are determined from a partially oriented polycrystalline sample via coherent inelastic neutron scattering. The largely quasi‐isotropic nature of these Mn+1AXn phase elastic constants as previously predicted by density functional theory calculations is confirmed experimentally for Ti3AlC2 to be c44=115.3 ± 30.7 GPa. In contrast, Ti3SiC2 is confirmed to be shear stiff with c44=402.7 ± 78.3 GPa supporting results obtained by earlier elastic neutron diffraction experiments.

Ab initio study of the structure, elastic, and electronic properties of Ti3(Al1−nSin)C2 layered ternary compounds

“…The calculated values for the bulk modulus of Ti 3 SiC 2 and Ti 3 AlC 2 are 139 GPa and 182 GPa respectively. These values agree well with the reported value by Gray et al 47 , with less than 13% and 7% deviation respectively for Ti 3 AlC 2 and Ti 3 SiC 2 . Moreover, our results for Shear modulus of 87 GPa for Ti 3 AlC 2 although are lower than the reported experimental value in Table 3, the results of Ti 3 SiC 2 of 121 GPa are in good agreement with the reported value.…”

Ab initio Study of the Structure, Elastic, and Electronic Properties of Ti3(Al1-nSin)C2 Layered Ternary Compounds

“…These values agree well with the reported value by 32 , with less than 13% and 7% deviation respectively for Ti3AlC2 and Ti3SiC2. Moreover, our results for shear modulus of 87 GPa for Ti3AlC2 although are lower than the reported experimental value in Table 3, the results of Ti3SiC2 of 121 GPa are in good agreement with the reported value.…”

Creation of a boron carbide-based Ti3AlBC (312) MAX phase: a route to novel MXenes for energy storage

“…It was observed that, for both Ti 3 AlC 2 and Ti 3 AlBC compounds, C 11 is greater than C 33 , which is in line with research findings. 25 The bulk modulus ( B ), shear modulus ( G ), Young's modulus ( Y = 9 BG /(3 B + G )), 26 and Poisson's ratio of Ti 3 AlBC were calculated. The bulk modulus of Ti 3 AlBC was estimated to be 139 GPa.…”