The Metadynamic Recrystallization Role in Ultrafast <111> Fiber Texture Evolution During Short-Term Holding in β-Forged Ti-6242

TL;DR

This study shows how a brief pause after forging titanium alloy Ti-6242 can rapidly change its microstructure through a process called metadynamic recrystallization.

Contribution

The paper identifies metadynamic recrystallization as the mechanism behind ultrafast texture evolution in Ti-6242 during short-term holding.

Findings

A <111> fiber texture forms within 1–3 seconds of holding due to metadynamic recrystallization.

Longer holds lead to static recrystallization and grain growth, diluting the <111> fiber texture.

Short-term holding can be used to control microtexture and reduce fatigue susceptibility in Ti-6242.

Abstract

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 <111> fiber texture develops along the forging axis, superseding the original <100> 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 <111>-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 <111> 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.

Figures