Influence of alloy element partitioning on strength of primary α phase in Ti-6Al-4V alloy

• Published in: Journal of materials science & technology 2018-05, Vol.34 (5), p.782-787
• Main Authors: Zeng, L.R., Chen, H.L., Li, X., Lei, L.M., Zhang, G.P.
• Format: Article
• Language: English
• Subjects: Alloy element partitioning; Crystallographic orientation; Nanoindentation; Strength; Ti-6Al-4V
• ISSN: 1005-0302; 1941-1162
• DOI: 10.1016/j.jmst.2017.07.016

The partitioning effect of Al (α-phase stabilizer) and V elements (β-phase stabilizer) on strength of the primary α phases in the α/β Ti-6Al-4V alloy with the bimodal microstructure was investigated. It was found that partitioning of Al and V elements took place in the Ti-6Al-4V alloy during the recrystallization process, leading to the variation of the content of Al and V elements in the primary α phases with changing the volume fraction of the primary α phase. Nanoindentation tests reveal a general trend that the strength of the primary α phases increases with decreasing the volume fraction of the primary α phases, and such trend is independent on the loading direction relative to the c-axis of the α phase. The enhanced strength is attributed to the increase of the content of Al element in the primary α phase, but it is not dominated evidently by the change of the V content. The solid solution strengthening contributed from both the elastic strain introduced by the solute atoms and the variation of the density of states was estimated theoretically.