Suppression Of Embrittlement Research Articles

Suppression of grain boundary embrittlement of Al–5% Mg alloy by immersion in liquid indium

High-temperature embrittlement (HTE) of coarse-grained Al–5% Mg alloy was suppressed by immersion in liquid indium. Characterization using scanning electron microscopy–energy dispersive X-ray spectrometry revealed that this treatment changed the fracture mode from intergranular to transgranular. Indium–sodium binary compounds were also identified at the grain boundaries after fracturing. The suppression of embrittlement was believed to arise from the reduction of accumulated sodium atoms at the grain boundary caused by replacement with indium–sodium compounds.

Suppression of moisture-induced embrittlement of Ni3(Si, Ti) alloys by a surface nickel alloying layer

The effect of a surface nickel alloying layer on moisture-induced embrittlement of Ni3(Si, Ti) alloys has been investigated by tensile tests at room temperature, using nickel-deposited materials. Undeposited Ni3(Si, Ti) alloy became remarkably embrittled in air. However, nickel-deposited Ni3(Si, Ti) alloy showed a high elongation value, indicating the suppression of embrittlement caused by hydrogen decomposed from moisture in the air. When the surface nickel alloying layer consists of f c c(γ) solid solution with a high nickel concentration and good adhesion to the substrate, improvement of tensile elongation is the greatest. The results have been discussed from the chemical and structural viewpoints of the surface nickel alloying layer.