Non-equilibrium grain-boundary segregation of Bi in binary Ni(Bi) alloy

The minimum ductility of Ni(Bi) alloy caused by isothermal annealing at 750 °C or 650 °C is determined through tensile tests at room temperature. Tensile samples with minimum ductility display intergranular facets. Strong grain-boundary segregation of Bi in nanocrystalline Ni-Bi layer is observed by atom probe tomography. The minimum ductility, intergranular facets and grain-boundary segregation of Bi confirm the non-equilibrium grain-boundary segregation of Bi in Ni(Bi) alloy for the first time.