Dynamic Recrystallization in Titanium Alloys: A Comprehensive Review

Abstract

This article is an attempt at highlighting recent advances made for understanding and modeling the phenomenon of dynamic recrystallization (DRX) prevalent in titanium alloys. Research work in recent years has focused on providing a rigorous description of key factors that influence the DRX process such as the effect of grain size, stacking fault energy, and other microstructural descriptors, thermomechanical processing, etc. The key addition of this work to existing literature is a critical commentary of important experimental as well as modeling efforts in recent years related to observing DRX in hexagonal close-packed (hcp) metals. We have attempted to directly compare, with reference to experiments, the effects of process variables such as strain rate, temperature, and composition on the occurrence of DRX in titanium alloys. A comprehensive review has been made of the experiments that have been carried out specifically to observe DRX in titanium alloys. This can aid modeling and validation efforts to accurately capture different facets of DRX for titanium alloys and other hcp metals. A similar comparison of the drawbacks and insights obtained from applying various modeling strategies, viz., FEM-based, phenomenological, or grid-based numerical methods for various alloys can provide valuable insights to choose appropriate modeling schemes or develop novel techniques to predict aspects of DRX such as preferred nucleation sites and evolution of microstructure, including grain boundaries and primary and secondary phases.

Direct Powder Forging—A New Approach for near Net Shape Processing of Titanium Powders

“…As it was mentioned, recrystallization was only observed in the core of the neck region. The utilization of a low strain rate during β-phase forging is likely to generate more dynamic recovery (DRV) than dynamic recrystallization (DRX) because, the high self-diffusivity of β-Ti and the decreasing store energy favor easier deformation but lower recrystallization [33][34][35][36][37]. During the final precision forging stage, high heat transfer from the dies allowed for a rapid cooling at the sample surface, which created a temperature gradient with the core.…”

Flow behavior and dynamic transformation of titanium alloy Ti62A during deformation at different temperatures and strain rates

“…The mechanical properties of dual-phase Ti alloys are particularly sensitive to hot deformation parameters and mechanisms [4,5], with work hardening (WH), dynamic recovery (DRV), and dynamic recrystallization (DRX) occurring during high-temperature deformation. The main microstructure evolution mechanisms during the thermal deformation of dual-phase titanium alloys are DRV and DRX.…”

Evaluating the influence of deformation variables on dynamic recrystallization behavior using a crystal plasticity model

“…Hence, it is frequently used to impart optimum strength as well as ductility to metals and alloys. A detailed discussion of DRX is presented in the reviews of Doherty et al [4], Sakai et al [5] and others [6,7].…”

“…Mean field homogenization (MFH) methods [9][10][11][12] consider the averaged values of grain sizes, shapes, and crystallographic orientations. However, full field homogenization (FFH) approaches [13][14][15][16] include full-field solutions of homogeneous boundary value problems of a microscale representative volume element [7]. FFH approaches are computationally more expensive as compared to MFH approaches.…”