Recent Advances in the Design of Novel β‐Titanium Alloys Using Integrated Theory, Computer Simulation, and Advanced Characterization

Abstract

Metastable β‐titanium (β‐Ti) alloys, because of their combination of high specific strength, superior corrosion resistance, and excellent biocompatibility, have found increasingly widespread application in aerospace, automobile, biomedical, and chemical industries. Many different pathways, available for phase transformation and deformation between a high‐temperature β and a low‐temperature α phase, provide ample opportunities to engineer the desired microstructure through thermal mechanical processing for optimal properties targeting specific applications. Based on an integrated approach (theory, crystallography, multiscale modeling, and advanced characterization), recent studies have obtained fundamental insights in both designing strategies by exploring a variety of nonconventional solid‐state phase transformation and deformation pathways, including 1) pseudospinodal decomposition; 2) precursory ω‐phase‐assisted α precipitation with a wide range of tunable size scales and number densities; and 3) abnormal high‐index deformation twinning modes. Herein, the revolutionary new concepts for alloy development and deployment and the underlying physical mechanisms are reviewed in detail. Perspectives on the future research directions in the development of metastable β‐Ti alloys are also offered. The mechanisms and alloy design concepts as well as the advantage of using state‐of‐the‐art computational and characterization tools in a correlative manner for alloy design are applicable to a wide range of metallic materials beyond Ti alloys.

Pore and grain chemistry during sintering of garnet-type Li6.4La3Zr1.4Ta0.6O12 solid-state electrolytes

“…Please do not adjust margins Please do not adjust margins field model, developed by the present authors 33,46 , accounts for multiple transport mechanisms operating during sintering, including surface transport (such as surface diffusion, lattice diffusion from the particle surface to the sintering neck, vapor transport through evaporation and condensation) and bulk transport (such as grain boundary (GB) diffusion and lattice diffusion from the GB to the pore). The latter transport mechanism leads to densification (i.e., reduction in particle spacing) while the former does not.…”

“…To gain a better understanding of the pore evolution and densication kinetics during sintering, a multi-phase eld model was also employed to study the microstructure (including solid grains and pore) evolution from a green-body with the same particle size distribution as the realistic pellets informed by experimental SEM characterization. The phase-eld model, developed by the present authors, 33,46 accounts for multiple transport mechanisms operating during sintering, including surface transport (such as surface diffusion, lattice diffusion from the particle surface to the sintering neck, vapor transport through evaporation and condensation) and bulk transport (such as grain boundary (GB) diffusion and lattice diffusion from the GB to the pore). The latter transport mechanism leads to densication (i.e., reduction in particle spacing) while the former does not.…”

Twinning–Detwinning Deformation Mechanism in Ti–15Mo Alloy and Its Effect on the Microstructure Evolution and Yield Strength

“…[ 27 ] As a summary, {332}<113> twinning has attracted increasing attention in the design of metastable β–Ti alloys with simultaneous improvement of strength and ductility. [ 5,27–29 ]…”

“…[27] As a summary, {332}<113> twinning has attracted increasing attention in the design of metastable β-Ti alloys with simultaneous improvement of strength and ductility. [5,[27][28][29] Recently, pre-twinning has been used as an effective method to enhance the strength of metallic materials. [30][31][32][33] For example, Xin et al reported that the introduction of f1012g twins in a prerolled AZ31 alloy can cause a significant increase in yield strength compared to the as-received alloy.…”