The effect of boron on grain boundary character distribution in two B-doped (500 and 2000ppm[wt]) Ni-24Al alloys was studied. The results were summarized as follows: (1) B reduced ∑3 boundaries from 14.8 to 5.9% when it increased from 500 to 2000ppm[wt], , respectively. This reduction could be interpreted in terms of the increase in stacking fault energy by the B addition. (2) No noticeable effect of B upon the frequency of occurrence of low-angle boundaries was observed. (3) When the ∑3 boundaries were excluded from the frequency distribution, the influence of B upon the fraction of RBs was negligibly small, suggesting that RBs were not affected by the presence of B. (4) The beneficial effects of B on the ductility of Ni3Al cannot be attributed to the change in grain boundary character distribution because B reduced the fraction of ∑3 boundaries and had no noticeable influence upon the occurrence of low-angle boundaries.

Effect of Boron on Grain Boundary Character Distribution in Ni3Al. Zhou, B., Gao, M., Chou, Y.T.: Scripta Materialia, 1997, 37[3], 341-6