Strengthening contributions of strong ordered precipitates

Abstract

The Hanson-Morris solution for the critical resolved shear stress of a random array of point obstacles is modified and applied to strong ordered precipitates. The solution approximately accounts for the effects of dislocation self-interactions and elastic anisotropy. The modified solution leads to a simple relationship between the antiphase boundary energy and the minimum looped precipitate diameter. This relationship is used to predict antiphase boundary energies for Al₃Li and Ni₃Al of 57 ± 15 mJ m⁻² and 102 ± 35 mJ m⁻². These values are in good agreement with recent determinations of the antiphase boundary energy by other techniques.