Non-uniform mechanical behaviour of uniaxially rolled Ti–6Al–4V with micro-texture regions

Hijazi, F and Roy, B and Srinivasan, D and Jayaram, V and Kumar, P (2023) Non-uniform mechanical behaviour of uniaxially rolled Ti–6Al–4V with micro-texture regions. In: Materials Science and Engineering A, 869 .

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Abstract

Uniaxial strain rate controlled and creep behavior of a unidirectionally rolled Ti–6Al–4V with micro-texture regions (MTR) were studied. The presence of MTR was identified and characterized using polarized light microscopy (PLM) and correlated with electron back-scatter diffraction (EBSD). Uniaxial tests were carried out along the rolling (RD), transverse (TD) and normal (ND) directions. Uniaxial strain rate controlled tests at strain rates of 10−3, 10−4 and 10−5 s−1 showed noticeable strain rate sensitivity at both room temperature (RT) and 200 °C. The yield strength in RD and TD was higher than ND by 16% and 8%, respectively. Creep behavior was sensitive to the initial strain rate during loading. The creep strain was fitted to a Norton-Bailey power law, ε=Aσntα, where ε, σ and t are creep strain, stress and time, respectively and A, n and α are constants, and showed a primary stress exponent, n, of 15 at RT and 10.4 at 200 °C and a time exponent, α, of 0.31 at RT and 0.125 at 200°C. In a first-of-its-kind exercise, PLM-EBSD was augmented with DIC in uniaxial strain rate controlled and creep tests for precise strain measurement and microstructural correlation with the directionality of testing. It revealed a significant effect of MTR on strain localization which may explain the role of MTR in failure nucleation.

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:	Creep; Digital image correlation; Micro-texture regions; Polarized light microscopy
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	02 May 2023 10:21
Last Modified:	02 May 2023 10:21
URI:	https://eprints.iisc.ac.in/id/eprint/81247

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