Experimental study of through-depth residual stress in explosive welded Al–Cu–Al multilayer

Explosive welded multi-layers sheet metals are widely used in recent years. Evaluation of residual stresses of this new merging material is necessary for better understanding of its mechanical behavior. In this paper, incremental hole-drilling (IHD) is used to measure through-depth non-uniform residual stress gradient in explosive welded Al–Cu–Al multilayers. At first, the multilayer sheets at two different initial thicknesses were made by using explosive welding. Then, through-depth residual stress gradient was obtained with the IHD method. In addition, calibration coefficients have been obtained to evaluate the residual stress by using finite element method (FEM) analysis. Results show that multilayers surface is subjected to high tensile residual stress. Also there is an intense gradient of residual stress at the interface of multilayers.

► We used hole-drilling to obtain residual stress in explosive welded multilayers.
► There is an intense variation of residual stress in interface of multilayers.
► Tensile residual stress occurs on the surface of multilayers.
► Initial thickness of multilayers does not effect on the in-depth residual stress.