Measurement of Residual Stress in As-Quenched 7055 Aluminum Plate by Various Methods

The accuracy of different residual stress measurement methods has always been the research focus from the beginning of research on residual stress. In this study, both conventional and newly-developed methods were applied to measure the residual stress in as-quenched 7055 aluminum plate. Methods such as hole drilling, X-ray diffraction based on sin²Ψ and cos α approaches, crack compliance method and neutron diffraction method were used. In the meanwhile, finite element simulation was used to obtain the residual stress distribution as a comparison. The results showed that among the methods studied, X-ray diffraction method has the greatest test error due to its shallow test depth. However, if the measurement condition was well controlled, the error could be acceptable. The absolute values of residual stress obtained by X-ray diffraction method were slightly greater than hole drilling method. If calculated with the reasonably chosen crack compliance function, the test result was similar to neutron diffraction method. Under different quenching conditions, all the studied methods showed that the greater the quenching cooling rate, the greater the absolute value of residual stress.