Constitutive behavior of aluminum alloy in a wide temperature range from warm to semi-solid regions

The constitutive behavior of aluminum alloy 7075 was characterized using compression tests performed over a wide range of temperatures (350-600 degrees C, from warm deformation temperature to semi-solid region) and strain rates (10(-3)-1 s(-1)). This work is of significance for the development of compound forming which combines plastic forming and semi-solid processing. The constitutive behavior in the wide temperature range was divided into two types: plastic deformation when the alloy is in solid state and containing a small fraction of liquid (350-490 degrees C); thixotropic deformation when the alloy is in the semi-solid state (above 490 degrees C). An adjusting factor which denotes the effect of liquid on the constitutive behavior was proposed. The constitutive model of peak stress as a function of temperature and strain rate was obtained for the wide range of temperatures (350-600 degrees C). The average relative errors between the calculated and measured values are 3.88% (350-490 degrees C) and 4.189% (above 490 degrees C), respectively. (C) 2016 Elsevier B.V. All rights reserved.