The Influence of Second-Phase Dispersion on Environmental Embrittlement of Ni3(Si, Ti) Alloys

Abstract

ABSTRACTSome quaternary Ni3(Si, Ti) alloyed with transition elements V, Nb, Zr and Hf was prepared beyond their maximum solubility limits to investigate the effect of second-phase dispersion on moisture-induced embrittlement. V-added Ni3(Si, Ti) alloy contained ductile fcc-type Ni solid solution as the second-phase, while Nb-, Zr- and Hf-added Ni3(Si, Ti) alloys contained hard dispersion compounds as the second-phase. V- and Nb-added Ni3(Si, Ti) alloys did not display reduced tensile elongation in air, indicating that their second phases have the effect of suppressing the moisture-induced embrittlement. Possible mechanisms for the beneficial effect by the second phase on the moisture-induced embrittlement of V- and Nb-added Ni 3(Si, Ti) alloys are discussed in association with hydrogen behavior and deformation property in the constituent phases or at matrix/second-phase interface.