Constitutive modelling of aluminium alloy sheet at warm forming temperatures

[摘要] The formability of aluminium alloy sheet can be greatly improved by warm forming. However predicting constitutive behaviour under warm forming conditions is a challenge for aluminium alloys due to strong, coupled temperature- and rate-sensitivity. In this work, uniaxial tensile characterization of 0.5 mm thick fully annealed aluminium alloy brazing sheet, widely used in the fabrication of automotive heat exchanger components, is performed at various temperatures (25 to 250 °C) and strain rates (0.002 and 0.02 s-1). In order to capture the observed rate- and temperature-dependent work hardening behaviour, a phenomenological extended-Nadai model and the physically based (i) Bergstrom and (ii) Nes models are considered and compared. It is demonstrated that the Nes model is able to accurately describe the flow stress of AA3003 sheet at different temperatures, strain rates and instantaneous strain rate jumps.

[发布机构] University of Waterloo, Waterloo; ON; N2N 3G1, Canada^1;Dana Canada Corporation, Oakville; ON; L6K 3E4, Canada^2

[关键词] Aluminium-alloy sheets;Brazing sheet;Constitutive behaviour;Physically based;Rate sensitivity;Temperature dependent;Uniaxial tensile;Work hardening behaviours