Microstructure evolution and mechanical response of a boron-modified Ti–6Al–4V alloy during high-pressure torsion processing

Roy, S and Sharma, A and Chaudhuri, A and Huang, Y and Langdon, TG and Suwas, S (2022) Microstructure evolution and mechanical response of a boron-modified Ti–6Al–4V alloy during high-pressure torsion processing. In: Materials Science and Engineering A, 860 .

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Abstract

Research was conducted on the microstructural evolution and ensuing mechanical response from high-pressure torsion (HPT) processing of Ti–6Al–4V alloy in the as-cast and β-forged conditions with and without 0.1 wt% boron addition. The boron addition produces refinement of the prior β grains and the (α+β) colonies and introduces an additional TiB phase but this affects the deformation response and the microstructural evolution only at low strains of 0.5–5 rotations. In the initial condition the orientation of the (α+β) colonies significantly affects the deformation response and leads to differences in substructure formation in both the as-cast and β-forged conditions. This orientation dependence counts on the initial microstructural differences between the unmodified and the boron modified alloys. At higher strains, there is a similar deformation response and microstructure evolution for all the alloys. The hardness variation with equivalent strain is similar for the unmodified and boron modified alloys in as-cast and β-forged conditions and represents various deformation regimes in HPT-processing. Strength modelling confirms a simultaneous contribution from microstructural refinement and increased dislocation density towards the hardness increment during HPT processing. Overall, the as-cast and β-forged Ti–6Al–4V-0.1B alloys possess identical deformation response to the β-forged unmodified Ti–6Al–4V alloy in the initial and intermediate stages. At high levels of straining, all alloys respond in an equivalent manner, thus ruling out any possible effects from additional TiB phase or microstructural refinement for the boron-modified alloys.

Item Type:	Journal Article
Publication:	Materials Science and Engineering A
Publisher:	Elsevier Ltd
Additional Information:	The copyright for this article belongs to Elsevier Ltd.
Keywords:	Deformation; Microstructural evolution; Strain; Titanium alloys; Titanium compounds; Torsional stress; X ray diffraction, As-cast; Boron modification; Condition; Deformation response; Hardness and strength modeling; High pressure torsions; Microstructure evolutions; Strength models; Ti-6al�4v alloy; X ray diffraction line profile analysis, Hardness
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	03 Jan 2023 04:51
Last Modified:	03 Jan 2023 04:51
URI:	https://eprints.iisc.ac.in/id/eprint/78620

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