Intermediate temperature embrittlement in high-purity Ni and binary Ni(Bi) alloy

Zheng L., Chellali R., Schlesiger R., Baither D., Schmitz G.

Zusammenfassung

The tensile ductility of high-purity Ni and binary Ni(Bi) alloy were studied in the temperature range of 400–850 oC. Ni(Bi) alloyshows evident intermediate temperature embrittlement with a minimum ductility between 700 and 750 oC, while high-purity Ni doesnot. It is concluded that this embrittlement must be an impurity effect. On the basis of quantitative estimates, the embrittlement isinterpreted as being caused by thermo-induced non-equilibrium grain-boundary segregation of Bi.