The impact of the torsional component on the microstructure and mechanical characteristics of a titanium alloy is examined in this work using a combination of numerical simulation and experimental validation. During the axial closed die rolling (ACDR) forming, the combined effects of compressive and torsional deformation cause a significant increase in the specimen’s cumulative strain. The specimen’s shear strain changes most significantly at the height of H/2. The α-phase has a greater propensity to slip on the conical surface, followed by the cylindrical surface, according to SEM and EBSD analyses. The basal surface has the highest resistance to slip. The formation of a fine isometric α-phase occurs when the compressive component causes the α-phase to become more prone to breakage and fracture. A larger α-phase will form because of the torsional component’s influence, which increases the likelihood that the α-phase will slip and exhibit bending and twisting. With a difference in strength of less than 1 percent and a difference in plasticity between the tangential and radial directions of less than 5 percent, the mechanical properties of the TC11 disks formed by the ACDR show a greater degree of isotropy. The specimens show a tough fracture mode, with radial performance outperforming tangential performance, according to fracture morphology analysis.

The torsional behavior during the deformation process of the axial closed die rolling the axial closed rolling (ACDR) forming is studied in this paper using a numerical simulation technique on TC11 titanium alloy. The axial and radial pinch angles, as well as the degree of specimen torsion, increased with the amount of deformation. The orientation distribution function (ODF) maps of the α-phase and β-phase were obtained by Electron Back Scatter Diffraction (EBSD) treatment of the TC11 titanium alloy. It can be noticed that there were different types of texture with different strengths in the ACDR samples, and in the xz and yz planes, textures in the direction of the column were predominantly of {0001} and {01$\overline{1}$0} ; the weaker the texture was, the closer to the edge of the sample. In the xy plane, the texture structure was mainly distributed along the cone direction, and the textures were {$\overline{1}$2$\overline{1}$0} and {01$\overline{1}$0} . However, the closer to the edge position of the specimen, the higher the intensity of the texture, and the texture was {1$\overline{2}$1$\overline{2}$} . The β-phase is mainly distributed as {001} , {110} , and {110} textures within the specimen, and the texture strength is about 8.5 times. However, owing to the small proportion of the β-phase content in the specimen, the distribution pattern of its texture has a weak impact on the texture distribution of the overall specimen. A high degree of isotropy in the radial and tangential tensile properties, with a strength isotropy of over 99 percent and a plasticity isotropy of over 95 percent, resulted from the distribution of texture types with varying strengths and orientations within the ACDR specimens, which weakened the TC11 discs’ overall orientation.

The Ti-6242 titanium alloy samples were forged at 1020 °C (slightly above the β-transus) and subjected to ultra-short isothermal holding (0–320 s) prior to quenching to investigate the rapid microstructural evolution in the parent β phase. Electron backscatter diffraction (EBSD) with parent β-phase reconstruction reveals that within only 1–3 s of holding, a pronounced fiber texture develops along the forging axis, superseding the original deformation fiber. This ultrafast texture change is attributed to metadynamic recrystallization (MDRX)—the post-deformation growth of nuclei formed during dynamic deformation. The newly formed -oriented β grains still contain residual substructure, indicating incomplete strain release consistent with MDRX. Longer holds (tens of seconds) lead to more extensive static recrystallization and normal grain growth, which dilute the strong fiber as grains of other orientations form and coarsen. These findings demonstrate that even a brief pause after forging can markedly alter the prior β texture via a MDRX mechanism. This insight highlights a novel approach to microtexture control in Ti-6242: by leveraging MDRX during short holds, one can potentially disrupt the formation of aligned α colony microtextured regions (MTRs, or “macrozones”) upon subsequent cooling, thereby mitigating dwell-fatigue susceptibility. The study revises the interpretation of the recrystallization mechanism in short-term holds and provides guidance for optimizing β-phase processing to improve fatigue performance.

This study proposes a novel framework for quantifying curved grain boundaries that overcomes key limitations of existing methods. Unlike Fourier-based approaches that require labor-intensive sequential analysis of individual boundaries and selectively represent only high-amplitude regions, or spline-based methods that demand complex parameter selection for interpolation points, the proposed framework integrates curvature variance filtering with U-chord curvature calculation to enable automated, comprehensive, and noise-resistant characterization of grain boundary morphology. The curvature variance filtering adaptively determines smoothing parameters based on local curve properties, while the U-chord curvature method ensures rotational invariance and robustness against digitization errors. Four heat treatment processes were applied to GH4169 alloy, producing distinct grain boundary morphologies with mean curvature (MC) values ranging from 0.0625 to 0.1252. Controlled cooling alone (Process A) yielded predominantly straight boundaries (91.06% straight, 0.12% serrated), while re-dissolution treatment (Process D) produced the highest serration degree (58.81% straight, 3.53% serrated). The quantitative analysis reveals that dispersed δ-phase precipitation creates discrete pinning points, forming serrated boundaries with sharp curvature peaks, whereas dense, parallel δ-phase arrays at specific angles produce coordinated wavy undulations. This framework provides a reliable quantitative tool for optimizing heat treatment protocols to achieve target grain boundary configurations in nickel-based superalloys.