An Experimental Investigation of Residual Stresses in High-Speed End Milling 7050-T7451 Aluminum Alloy

A high-speed milling experiment by means of orthogonal method with four factors was conducted for aluminum alloy 7050-T7451. The residual stresses (RS) on the surface and subsurface of the work piece were measured using X-ray diffraction technique and electropolishing technology. The exponent's mathematical model for milling residual stress of 7050-T7451 aluminum alloy was established related to machining parameters. The predicted values were compared with the data from experiments. The effect of cutting speed, feed rate, and width and depth of cut on residual stress was investigated using the ANOVA techniques. The affecting degree of milling parameters are shown as v > f z > a p > a e in order. The influence trend of milling factors on residual stresses was also studied; the machine-induced residual compressive stresses tend to decline with the increase of cutting speed and decrease of the feed rate.