Mechanisms underlying enhanced strength-ductility combinations in TRIP/TWIP Ti-12Mo alloy engineered via isothermal omega precipitation

Qian，Bingnan1,2; Mantri，Srinivas Aditya3,4; Dasari，Sriswaroop3,4; Zhang，Jinyong5,6; Lilensten，Lola1; Sun，Fan1; Vermaut，Philippe1,7; Banerjee，Rajarshi3,4; Prima，Frédéric1

2023-02-15

10.1016/j.actamat.2022.118619

ACTA MATERIALIA   Impact Factor & Quartile

1359-6454

β Ti-alloys can achieve a high strain-hardening rate and tensile ductility by taking advantage of transformation induced plasticity (TRIP) and twinning-induced plasticity (TWIP) effects. While nano-precipitation of isothermal ω (ω) can have a substantial strengthening effect in these alloys, it usually has a detrimental effect on ductility leading to embrittlement. To overcome the above problem, this work proposes as a novel strategy based on coupling of ω formation and mechanical twinning/martensitic transformation to enhance the strength while preserving good ductility in case of the TRIP/TWIP Ti-12Mo alloy. An unprecedented combination of tensile properties, yield stress at 865MPa (80% higher than classic Ti-12Mo) with uniform elongation of 0.35, are recorded after 200C aging for 60s. Higher yielding stress (990MPa) is achieved when increasing the aging duration to 150s where mechanical twinning is still active. In-situ investigations under traction/heating, and atom probe tomography are performed to clarify the ω formation process and the interactions between ω phase and the operating deformation mechanisms, i.e. mechanical {332}<113> twinning, β → α″ martensitic transformation and dislocation glide. The early stages of formation of ω precipitates, mediated via Mo partitioning at low aging temperature, and its consequent impact on the deformation mechanisms operative in the β matrix has been characterized. The transformation partition mapping method, based on statistical electron backscatter diffraction characterization developed in our previous work, is employed to individually assess the evolution of the critical resolved shear stresses of each operating deformation mechanism as a function of the ω nucleation.

Deformation twinning Mechanical properties Omega phase Phase transformation Titanium alloys

SCI

English

Others

WOS:000909599900001

MATERIALS SCIENCE

2-s2.0-85144371765

Scopus

1.PSL University,Chimie ParisTech,CNRS,Institut de Recherche de Chimie Paris,Paris,75005,France
2.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,518055,China
3.Department of Materials Science and Engineering,University of North Texas,Denton,7620,United States
4.Center for Advanced Research and Technology,University of North Texas,Denton,7620,United States
5.School of Material Science and Engineering,China University of Mining and Technology,Xuzhou,221008,China
6.State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an,710072,China
7.Sorbonne Universities,UPMC University Paris,UFR926,Paris,75006,France

Qian，Bingnan,Mantri，Srinivas Aditya,Dasari，Sriswaroop,et al. Mechanisms underlying enhanced strength-ductility combinations in TRIP/TWIP Ti-12Mo alloy engineered via isothermal omega precipitation[J]. ACTA MATERIALIA,2023,245.

Qian，Bingnan.,Mantri，Srinivas Aditya.,Dasari，Sriswaroop.,Zhang，Jinyong.,Lilensten，Lola.,...&Prima，Frédéric.(2023).Mechanisms underlying enhanced strength-ductility combinations in TRIP/TWIP Ti-12Mo alloy engineered via isothermal omega precipitation.ACTA MATERIALIA,245.

Qian，Bingnan,et al."Mechanisms underlying enhanced strength-ductility combinations in TRIP/TWIP Ti-12Mo alloy engineered via isothermal omega precipitation".ACTA MATERIALIA 245(2023).