Evaluation of residual stress relief of aluminum alloy 7050 by using crack compliance method
(1.Electromechanical Engineering College,
Zhejiang University of Technology, Hangzhou 310032, China;
2.College of Mechanical and Energy Engineering,
Zhejiang University, Hangzhou 310027, China;
3.Architectural Engineering College,
Zhejiang University of Technology, Hangzhou 310032, China)
Zhejiang University of Technology, Hangzhou 310032, China;
2.College of Mechanical and Energy Engineering,
Zhejiang University, Hangzhou 310027, China;
3.Architectural Engineering College,
Zhejiang University of Technology, Hangzhou 310032, China)
Abstract: High strength aluminum alloys of 7xxx series have unacceptable levels of quenching residual stresses from solution heat treatment. The residual stress not only results in machining distortion and dimensional instability, but also increases the possibility of stress corrosion cracks. Therefore, it is necessary to reduce the residual stress to an acceptable level. The crack compliance method was adopted to study the influences of various stress relief methods on residual stress patterns in 7050 aluminum alloy. The results show that 90% residual stress can be eliminated by the cold stretching(Tx51) method. And a lower level of residual stress can be achieved by the uphill quenching(Tx53) method or the cold compression(Tx52). However, there is a very steep residual stress gradient normal to exterior surfaces.
Key words: aluminum alloy; residual stress; stress relief; evaluation; crack compliance method