Ω phase strengthened 1.2GPa metastable β titanium alloy with high ductility. (15th March 2019)

• Record Type: Journal Article
• Authors: Gao, Junheng; Knowles, Alexander J.; Guan, Dikai; Rainforth, W. Mark
• Is Part Of: Scripta materialia. Number 162(2019)
• Page Start: 77
• Page End: 81
• Publication Date: 2019-03-15
• Subjects: Metastable beta titanium alloy -- ω phase -- Strengthening -- Yield strength; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2018.10.043
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: This paper provides a novel approach for exploiting ω phase strengthening in a metastable β titanium alloy while retaining high ductility. The addition of 1 wt% Fe into our previously designed Ti-7Mo-3Cr alloy can efficiently control the growth of ω phase following air-cooling, resulting in a ultrahigh yield strength ( R p 0.2 of 1210 MPa) with large ductility (εf of 0.15). Microstructural analysis of deformed alloys showed that the growth of ω phase in the air-cooled Ti-7Mo-3Cr-1Fe alloy modified the deformation mechanism from {332} twinning and dislocation slip, in the water-quenched alloy, to localized dislocation plasticity in ω-void channels. Graphical abstract: Stress-strain curves of both air-cooled and water-quenched Ti-7Mo-3Cr-1Fe and Ti-7Mo-3Cr alloy and their corresponding dark-field images showing the distribution of omega phase with different sizes; insets are their corresponding select-area electron diffraction patterns. (a) Air-cooled Ti-7Mo-3Cr-1Fe alloy, (b) water-quenched Ti-7Mo-3Cr-1Fe alloy, (c) air-cooled Ti-7Mo-3Cr alloy and (d) water-quenched Ti-7Mo-3Cr alloy. Unlabelled Image