Effect of boron on the fracture behavior and grain boundary chemistry of Ni3Fe

The effect of B on the fracture behavior of Ni3Fe alloys (24 and 26 at.% Fe) was studied after cathodic charging with hydrogen. In contrast to its disordered state, ordered Ni3Fe underwent brittle intergranular fracture at room temperature. Boron addition changed its fracture mode to predominantly ductile transgranular. The grain boundary chemistry of ordered Ni3Fe was analyzed by Auger electron spectroscopy. Boron was found to segregate to the grain boundaries of both Ni–24Fe and Ni–26Fe and reduce the hydrogen-induced embrittlement of these alloys in the ordered state.