Mesoscale modeling of dynamic recrystallization behavior, grain size evolution, dislocation density, processing map characteristic, and room temperature strength of Ti-6Al-4V alloy forged in the (alpha plus beta) region

摘要

This work focuses on a series of microstructural predictions regarding the dynamic recrystallization (DRX) behavior, change in grain size and dislocation density. Additionally, this study includes the prediction of the room-temperature-strength and the processing map characterization of Ti-6Al-4V alloy after forging in the (alpha+beta) region. The experimental tests of the forgings reveal that the mechanism of microstructural conversion depends on the testing conditions. That is, superplastic behavior is exhibited at lower strain rates and higher temperatures. With an increasing strain rate and decreasing temperature, DRX occurs in a continuous manner. A set of constitutive equations that model the microstructural evolution, processing map characteristics and room temperature strengths is established by optimization of experimental data, followed by implementation into the DEFORM-3D software package. There is satisfactory agreement between the experimental and simulated results. Thus, a series of constitutive models (established in this work) is found to enable the reliable prediction of properties of Ti-6Al-4V alloy after forging in the (alpha+beta) region. (C) 2017 Elsevier B.V. All rights reserved.