Thermal expansion/contraction behavior of AA7050 alloy in the as-cast condition relevant to thermomechanical simulation of residual thermal stresses

Abstract

Abstract As-cast 7xxx series aluminum alloys experience a severe loss in ductility upon cooling and become brittle below 300 °C. In order to simulate the thermal stresses arising during casting, a thorough understanding of the thermal contraction behavior during solidification and cooling is required. In this study, some thermal properties of the AA7050 alloy are determined experimentally in the “as-cast” condition. Solidification contraction tests were performed to determine the onset of thermal contraction in the grain refined alloy and dilatometry tests were conducted to estimate the coefficient of thermal expansion/contraction of the alloy. Our simulation results showed that although the temperature dependence of the coefficients of thermal expansion/contraction obtained from the tests differ from the predictions of thermodynamic data-base, these differences are not crucial to the results of the thermomechanical simulations.