Constitutive equation and dynamic recovery mechanism of high strength cast Al-Cu-Mn alloy during hot deformation. (December 2022)

• Record Type: Journal Article
• Authors: Shi, Dongjin; Zhang, Fan; He, Ziyu; Zhan, Zhaolin; Gao, Wei; Li, Zulai
• Is Part Of: Materials today communications. Volume 33(2022)
• Publication Date: 2022-12
• Subjects: Cast Al-Cu-Mn alloy -- Hot deformation -- Phenomenological constitutive model -- Isothermal compression -- Dynamic recovery; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2022.104199
• Languages: English
• ISSNs: 2352-4928

Abstract

Abstract: The hot deformation behavior and precipitates of cast AlCu4.4 Mn0.6 alloy has been investigated by compression tests in a Gleeble-3500 thermodynamic simulator at the temperature range of 200−290 °C and strain-rate range of 0.01−10 s −1 . The dynamic recovery (DRV) of AlCu4.4 Mn0.6 alloy in hot deformation was sensitive to temperature and strain-rate, and was accelerated by increasing the deformation temperature and strain-rate. The heat-treated AlCu4.4 Mn0.6 specimen exhibited high strength as the compressive flow stress was about 310 MPa at 290 °C and the strain-rate of 10 −1 . A accurate constitutive equation was established with the correlation coefficient (R) of 96.2 % and the average absolute relative error ( AARE ) of 4.65 %. The predicted flow stress was in good agreement with the experimental results. Nanoscale Ω, θ′ and T phases were uniformly distributed in the matrix of AlCu4.4 Mn0.6 alloy and hindered dislocation movement in hot deformation process, leading work hard (WH) of the alloy. Meanwhile the DRV promoted the dislocation annihilation and polygonization, resulting in the formation of sub-boundaries and the softening of the alloy. The flow stress was almost stable or gradually decreased with the increase of strain. Graphical Abstract: The constitutive equation was developed to accurately describe the hot deformation behavior of the cast AlCu4.4 Mn0.6 alloy deformed at 200−290 °C. The predicted flow stresses of AlCu4.4 Mn0.6 alloy compressed at 290 °C were in good agreement with the experimental results. ga1