Final published version
Licence: CC BY: Creative Commons Attribution 4.0 International License
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Alloy design by tailoring phase stability in commercial Ti alloys
AU - Zhao, G.-H.
AU - Liang, X.Z.
AU - Xu, X.
AU - Gamża, M.B.
AU - Mao, H.
AU - Louzguine-Luzgin, D.V.
AU - Rivera-Díaz-del-Castillo, P.E.J.
PY - 2021/5/20
Y1 - 2021/5/20
N2 - The mechanical characteristics and the operative deformation mechanisms of a metallic alloy can be optimised by explicitly controlling phase stability. Here an integrated thermoelastic and pseudoelastic model is presented to evaluate the β stability in Ti alloys. The energy landscape of β→α′/α″ martensitic transformation was expressed in terms of the dilatational and transformational strain energy, the Gibbs free energy change, the external mechanical work as well as the internal frictional resistance. To test the model, new alloys were developed by tailoring two base alloys, Ti–6Al–4V and Ti–6Al–7Nb, with the addition of β-stabilising element Mo. The alloys exhibited versatile mechanical behaviours with enhanced plasticity. Martensitic nucleation and growth was fundamentally dominated by the competition between elastic strain energy and chemical driving force, where the latter term tends to lower the transformational energy barrier. The model incorporates thermodynamics and micromechanics to quantitatively investigate the threshold energy for operating transformation-induced plasticity and further guides alloy design. © 2021 The Author(s)
AB - The mechanical characteristics and the operative deformation mechanisms of a metallic alloy can be optimised by explicitly controlling phase stability. Here an integrated thermoelastic and pseudoelastic model is presented to evaluate the β stability in Ti alloys. The energy landscape of β→α′/α″ martensitic transformation was expressed in terms of the dilatational and transformational strain energy, the Gibbs free energy change, the external mechanical work as well as the internal frictional resistance. To test the model, new alloys were developed by tailoring two base alloys, Ti–6Al–4V and Ti–6Al–7Nb, with the addition of β-stabilising element Mo. The alloys exhibited versatile mechanical behaviours with enhanced plasticity. Martensitic nucleation and growth was fundamentally dominated by the competition between elastic strain energy and chemical driving force, where the latter term tends to lower the transformational energy barrier. The model incorporates thermodynamics and micromechanics to quantitatively investigate the threshold energy for operating transformation-induced plasticity and further guides alloy design. © 2021 The Author(s)
KW - Alloy design
KW - Phase transformation
KW - Physical modelling
KW - Plasticity
KW - Ti alloys
KW - Free energy
KW - Friction
KW - Gibbs free energy
KW - Martensitic transformations
KW - Mechanisms
KW - Phase stability
KW - Strain energy
KW - Thermodynamic stability
KW - Titanium alloys
KW - Alloy designs
KW - Deformation mechanism
KW - Energy
KW - Martensitics
KW - Mechanical characteristics
KW - Metallic alloys
KW - Phases transformation
KW - Physical model
KW - Thermoelastic modeling
U2 - 10.1016/j.msea.2021.141229
DO - 10.1016/j.msea.2021.141229
M3 - Journal article
VL - 815
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
SN - 0921-5093
M1 - 141229
ER -