Constitutive equation and processing maps of an Al-Mg-Si aluminum alloy: Determination and application in simulating extrusion process of complex profiles

A deep understanding of hot deformation behavior of a material plays a crucial role in determining process parameters and designing extrusion dies during the extrusion process of the aluminum alloy profiles. Firstly, with the stress strain data obtained by hot compression tests of AA6N01, the material parameters in the Arrhenius constitutive model with strain compensation were identified, the processing maps were established according to dynamic material model (DMM), and favorite processing parameters of this alloy were accordingly determined. Then, the identified material parameters and processing parameters were applied to simulate the extrusion process of a complex cross-section profile used in manufacturing high-speed train body. To reduce the severe twist deformation in the cross-section of the profile, different die correction schemes (adding baffle plates, adjusting bearing lengths) were taken to improve material flow uniformity in the cross-section of the profile. Through a series of die modifications, the velocity uniformity was improved greatly. With the modified extrusion die, the complex cross-section AA6N01 profile was finally extruded with desired size and geometry. The good agreement between numerical results and experimental observations verified the constitutive model, process parameters and numerical model built in this work. (C) 2015 Elsevier Ltd. All rights reserved.