Hot deformation behavior of aluminum alloys: A comprehensive review on deformation mechanism, processing maps analysis and constitutive model description

Abstract

This article provides a detailed investigation of the intricate aspects of hot deformation, processing map assessment, and microstructural evolution in aluminum (Al) alloys. It also discusses the application of constitutive equations to forecast flow stress. This article explains how the hot working process can improve the grain structure of aluminum alloys utilizing dynamic recrystallization (DRX), mitigating flaws and strengthening their mechanical properties. Various aspects, such as the development of necklace structures, work-hardening analysis for identifying DRX grains, and the impact of processing conditions on DRX grain size, are thoroughly examined. The microstructural evolution, plastic deformability, and material properties of Al alloys were observed to be impacted by factors such as alloy composition, phase occurrences, deformation processing parameters, and recrystallization mechanisms. The article scrutinizes the use of processing maps to ascertain optimal conditions, addressing the instability regime—encompassing flow instability, defects, and cracking—during aluminum hot-working. Notably, the review delves into constitutive modelling of flow stress, considering factors like deformation strain rates, temperatures, and strain, and examining threshold stress resulting from phase transformation, temperature-dependent Young's modulus, and the alignment of experimentally observed activation energy and deformation stress exponent with values predicted by creep theories. Additionally, the study evaluates various modelling techniques and equations for predicting flow curves in the context of hot-working processing. The article concludes by offering recommendations for potential future research directions.