“…This is due to their intrinsically weak grain boundaries, caused by the structural state of the material, but these can be influenced for instance by the solidification procedure [S], by boron and other additions [3,4,5,6,7,8], or by the outer environment [9]. The countermeasure which has been studied most frequently is a boron addition, which can significantly enhance both ductility and yield strength [7]. Boron, however, may segregate [2] and thereby affect the structure and geometry of the grain boundaries, grain size and growth, and the cohesive strength of the grains [3,41 ; it may also modify the Ni3Al alloy by dissolving in it, thereby increasing the concentration of interstitials and macroscopically strengthening the matrix by increasing the resistance of the matrix and of its defects to dislocation glide [7].…”