Heterogeneous distribution of isothermal ω precipitates prevents brittle fracture in aged β-Ti alloys

Review Materials Science, Multidisciplinary

A review of the metastable omega phase in beta titanium alloys: the phase transformation mechanisms and its effect on mechanical properties

JoAnn Bailor et al.

Summary: The omega phase in titanium and its alloys has been a subject of research interest since its discovery in 1954. The debate on the transformation mechanisms, particularly the beta-to-omega and omega-to-alpha phase transformations in beta-titanium alloy design, continues. Advanced characterization methods have led to improved spatial resolution and compositional sensitivity in phase transformation analysis.

INTERNATIONAL MATERIALS REVIEWS (2023)

添加到收藏夹

Article Materials Science, Multidisciplinary

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

Bingnan Qian et al.

Summary: The work proposes a novel strategy to enhance the strength while preserving good ductility in the TRIP/TWIP Ti-12Mo alloy by coupling omega(iso) formation and mechanical twinning/martensitic transformation. After aging at 200 degrees C for 60s, an unprecedented combination of tensile properties is recorded, with a yield stress of 865MPa (80% higher than classic Ti-12Mo) and a uniform elongation of 0.35. Higher yielding stress (990MPa) is achieved with an increased aging duration of 150s, where mechanical twinning is still active.

ACTA MATERIALIA (2023)

添加到收藏夹

Article Materials Science, Multidisciplinary

Oxygen interstitials make metastable /3 titanium alloys strong and ductile

Yan Chong et al.

Summary: It has been found that grain refinement in the Ti-12Mo alloy leads to a decrease in ultimate tensile strength due to the softening effect of strain-induced α martensite phase. However, the addition of oxygen along with grain refinement in the Ti-12Mo-0.3O alloy results in a significant enhancement in both strength and ductility. This study provides valuable insights for the design of strong and tough metastable /3 titanium alloys.

ACTA MATERIALIA (2023)

添加到收藏夹

Article Nanoscience & Nanotechnology

Ultrahigh cryogenic strength and exceptional ductility at 20 K in a TWIP Ti-15Mo alloy

Kai Yao et al.

Summary: The tensile behavior of metastable beta-type Ti-15Mo alloy with {332}<113> twinning-induced plasticity (TWIP) effect was investigated at 20K. It was found that the alloy exhibited ultrahigh strength and excellent elongation, making it a major advancement for cryogenic applications. The serrated tensile curve and multiple necking observed were attributed to the formation of twins. The presence of abundant {332}<113> twins and piled-up dislocations at twin boundaries hindered local plastic deformation and necking, resulting in simultaneous enhancement of strength and ductility. Exploiting the {332}<113> TWIP effect in body-centered cubic (BCC) structured titanium alloys is a novel strategy for cryogenic alloy development.

SCRIPTA MATERIALIA (2022)

添加到收藏夹

Article Nanoscience & Nanotechnology

Revisiting ω phase embrittlement in metastable β titanium alloys: Role of elemental partitioning

M. J. Lai et al.

Summary: In Ti-12Mo alloy, rejection of Mo element from omega phase particles leads to intense plastic flow localization and crack nucleation, causing embrittlement, which occurs as early as 10 minutes of aging at 400 degrees Celsius.

SCRIPTA MATERIALIA (2021)

添加到收藏夹

Article Nanoscience & Nanotechnology