Temperature effect on superdislocation dissociation on a cube plane in Ni₃Al

Abstract

Temperature dependence of the apparent antiphase boundary (APB) energy on cube planes is studied using weak-beam determination of dissociation distances of superdislocations originating from deformation at 20,650 and 850°C. It is difficult to assess how closely the observed dependence applies to the true cube ABP energy because of the uncertainty associated with lattice resistance to the motion of superpartials. It is estimated that the true energy of conservative APB on {001} is liable to decrease with temperature as much as 30% between room temperature and 850°C.