Published online by Cambridge University Press: 26 February 2011
Grain boundaries in both pure and boron doped Ni3A1 have been studied using a variety of electron microscopy techniques. Small angle boundary structures were examined in both bicrystal and polycrystalline specimens. Dislocations with Burgers vector a/2<110> are observed in the presence of boron, while dislocations with Burgers vector a<100> are observed in the absence of boron. A possible explanation for this behaviour is the presence of a disordered layer at the interface in boron doped Ni3A1. The addition of boron to Ni3A1 was seen to induce faceting of grain boundaries, and to afford the boundaries some protection from etching. Using electron backscatter diffraction patterns, the frequency of occurrence of grain boundary types was found to be unchanged by the addition of boron.