ABSTRACT
A single-crystal constitutive model of the L1₂-structure intermetallic compound Ni₃ Al is developed, based on recent theoretical developments in dislocation mechanics and on experimental evidence. Hirsch's superkink-bypassing model and Caillard's self-unlocking mechanism have been modified and combined to describe dislocation dynamics in the yield anomaly region. Results of numerical simulations successfully capture major features of temperature dependence of the tensile yield strength and hardening rate over a range of crystallographic orientations.