The mechanical behavior of and deformation mechanisms in Al2Ti

The mechanical properties of the binary intermetallic compound Al2Ti show a strong dependence on test temperature and processing condition. The compressive yield strength and plastic strain-to-failure of Al2Ti as a function of temperature will be reviewed. Unlike many L12 compounds, binary Al2Ti with the Ga2Hf crystal structure, a body-centered tetragonal-based structure, does not show any evidence of anomalous yield strength behavior. Based on the crystallography of Al2Ti, various deformation modes are proposed. Possible partial dislocations and the planar faults that would be associated with them are hypothesized. The formation of antiphase boundaries (APBs) on {1 1 6}—the close-packed planes—and {1 0 0} and complex stacking faults (CSFs) on {1 1 6} will be discussed. It does not appear to be possible to form a superlattice intrinsic stacking fault (SISF) on {1 1 6}. Slip by 1/2〈1 1 0〉 partial dislocations on {0 0 1} with the formation of a stacking fault may also be an important deformation mechanism and will be discussed. Thermally-activated cross-slip of APB-coupled partial dislocations from {1 1 6} onto {1 0 0} is not expected to be important in this material based on the observed mechanical behavior.