The effect of boron on the chemistry of grain boundaries in stoichiometric Ni₃Al

Abstract

X-ray spectra have been obtained, using a 1 nm diameter electron beam, from thin foils of stoichiometric Ni₃Al with and without boron (0·35 at.%). The boron addition produces nickel enrichment at grain boundaries, which implies a disordering of this region. Disordering of the grain boundary and the consequent expected increase in grain boundary dislocation mobility are suggested to be the reason for the ductility improvement of Ni₃Al due to boron.