Deformation Mechanism and Microstructure Control of High Strength Metastable β Titanium Alloy

Near‐β titanium alloys are used as promising structural materials for aerospace, biomedical, and other advanced applications due to their excellent combination of high specific strength and superior corrosion resistance. Precise control of the microstructure and mechanical properties through thermomechanical processing and heat treatment is paramount for exploiting the full potential of these alloys. This review article provides a comprehensive and critical assessment of the state‐of‐the‐art research on the microstructure evolution, deformation mechanisms, and oxidation behavior of near‐β titanium alloys. Furthermore, the challenges and emerging opportunities in the development of near‐β titanium alloys have also been identified, ranging from alloy design and processing optimization to multiscale characterization and integrated computational materials engineering. This review article provides a timely and comprehensive roadmap for the research and development of near‐β titanium alloys, paving the way for unlocking their full potential in critical industries.

Research progress on microstructure evolution and hot processing maps of high strength β titanium alloys during hot deformation

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Strain rate affects the deformation mechanism of a Ti-55511 titanium alloy: Modeling of constitutive model and 3D processing map using machine learning

Microstructure evolution, mechanical properties and high temperature deformation of (TiB + TiC)/Ti–3.5Al–5Mo–6V–3Cr–2Sn–0.5Fe titanium alloy

An experimental study of deformation mechanism and microstructure evolution during hot deformation of Ti–6Al–2Zr–1Mo–1V alloy

Hot deformation characteristics and mechanism understanding of Ti–6Al–2Sn–4Zr–6Mo titanium alloy

The dynamic response of β titanium alloys to high strain rates at room and elevated temperatures

Due to attractive mechanical properties, metastable β titanium alloys have become very popular in many industries including aerospace, marine, biomedical, and many more. It is often the complex interplay among the different deformation mechanisms that produces many of the sought-after properties, such as enhanced ductility, super-elasticity, and shape memory effects. Stress induced martensitic transformation is an important deformation mechanism for these alloys. Understanding of it and the influence it has on the microstructural evolution of materials is of great importance. To this end we have developed a crystal plasticity based constitutive model which accounts for both martensitic phase transformation and slip based plasticity simultaneously in metastable β titanium alloys. We present a new formulation for the evolution of martensite transformation, based on physical principles and crystal plasticity theory. To understand and demonstrate this feature of the model, a parametric assessment of the newly developed constitutive model is conducted. This is followed by first of its kind analyses of stress induced martensitic transformation in metastable β titanium alloys. We firstly present validations against uniaxial loading experiments for different metastable β titanium alloys exhibiting stress induced martensite transformation. As part of this, single crystal simulations in metastable β titanium alloys are used for the first time to investigate the interaction of individual transformation systems during unconstrained transformation. This study shows good agreement between the experimental and simulated responses during all stages of deformation in which elastic, transformation and finally the slip stage are exhibited. Relatively ‘strong’ and ‘weak’ orientations for transformation are observed, consistent with experimental studies. The work done here demonstrates the ability of this crystal plasticity finite element method to capture physical mechanisms while bringing new insight about the interaction of different deformation mechanisms in metastable β titanium alloys.

Titanium alloy has the advantages of low thermal conductivity, a small expansion coefficient and being non-magnetic, making it an ideal low-temperature structural material. In this paper, the typical TC4 titanium alloy in industrial titanium alloy is selected as the research object. The microstructure deformation law and mechanical behavior of TC4 titanium alloy at liquid nitrogen temperature are mainly investigated, and compared with the microstructure and properties at room temperature. The macroscopic and microscopic deformation mechanism of the simultaneous increase in elongation and hardening index of titanium alloy at low temperature is revealed, which provides a basic basis for the low-temperature deformation mechanism and strengthening and toughening design of titanium alloy. Based on the uniaxial tensile tests at room temperature (298 K) and low temperature (77 K), the effects of low temperature on the yield strength, elongation, tensile strength and work hardening curve of titanium alloy were compared and analyzed. The strength/plasticity synergistic improvement of TC4 titanium alloy under low-temperature deformation was found. At low temperature, the yield strength, tensile strength and elongation of TC4 titanium alloy are improved compared with room temperature. The tensile strength increases from 847.93 MPa at 298 K to 1318.70 MPa at 77 K, and the elongation increases from 21.8% at 298 K to 24.9% at 77 K. The grain morphology, grain orientation, dislocation density and fracture morphology of titanium alloy under room temperature and low-temperature tensile conditions were studied by SEM and EBSD. The results of fracture morphology characterization at room temperature and low temperature show that TC4 titanium alloy exhibits ductile fracture characteristics and a large number of dimples are formed on the fracture surface. The dimple depth at low temperature is shallower than that at room temperature and the overall surface is more flat. Compared with room temperature deformation, the deformation process of TC4 titanium alloy in a low-temperature environment produces stronger dislocation pile-up and forms a large number of twins, but the grain rotation is more significant, which effectively alleviates the stress concentration and delays the initiation and propagation of cracks at grain boundaries.

Research on deformation law and mechanism for milling micro thin wall with mixed boundaries of titanium alloy in mesoscale

Deformation mechanism diagram and deformation instability of a Ti-5Al-5Mo-5V-1Cr-1Fe titanium alloy during the hot compression

Simultaneously improved strength and ductility of low-cost Ti-Al-V-Fe alloy with TiB2 addition and thermomechanical processing

Microstructure and creep deformation of a near beta titanium alloy ‘β-CEZ’

Hot deformation behavior originated from dislocation activity and β to α phase transformation in a metastable β titanium alloy