Environmental embrittlement of intermetallics

摘要

The effect of alloying elements on the environmental embrittlement of Ll_2 type intermetallics is sum- marized. The results show that the ductilizing effect of boron doping in Ni_3 Al is mainly to suppress the moisture-induced environmental embrittlement. The mechanism of this suppression effect is proved to lie in the fact that it severely reduces the hydrogen diffusivity along the grain boundaries. However, the boron doping in Co_3 Ti alloys does not have the same effect of suppressing the environmental embrittlement.