Abstract
The stress relaxation ageing behaviour and post-form mechanical properties of an Al-Zn-Mg alloy, AA7B04, have been experimentally investigated and modelled. The stress relaxation ageing tests were carried out under different initial stress levels and durations at 165 °C and subsequent tensile tests were performed at room temperature. The detailed effects of stress and time on stress relaxation and main post-form mechanical properties (yield strength, ultimate tensile strength, and uniform elongation) have been analysed and discussed. Based on the results and analysis, a set of unified constitutive equations has been developed for the first time to simultaneously predict stress relaxation ageing behaviour of the aluminium alloy during the creep age forming (CAF) process and the main mechanical properties of the products after CAF. The model comprises three sub-models, including microstructure, stress relaxation ageing and post-form mechanical properties, and has successfully predicted corresponding behaviour. The developed model provides an effective tool to not only predict the forming process but also support possible industrial applications for CAF products.
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Acknowledgments
The research in this paper was funded by the National Natural Science Foundation of China (52005020) and Guangdong Basic and Applied Basic Research Foundation (2019A1515110851). The strong support from the Aviation Industry Corporation of China (AVIC) Manufacturing Technology Institute (MTI) for this funded research is much appreciated. The experiments in this study were performed at the AVIC Centre for Structural Design and Manufacture at Imperial College London.
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Li, Y., Lyu, F., Shi, Z., Zeng, Y., Huang, X., Lin, J. (2021). Experimental Study and Modelling of Stress Relaxation Ageing Behaviour and Post-form Mechanical Properties in Creep Age Forming of Al-Zn-Mg Alloy. In: Daehn, G., Cao, J., Kinsey, B., Tekkaya, E., Vivek, A., Yoshida, Y. (eds) Forming the Future. The Minerals, Metals & Materials Series. Springer, Cham. https://doi.org/10.1007/978-3-030-75381-8_73
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DOI: https://doi.org/10.1007/978-3-030-75381-8_73
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