Deformation prediction and experimental investigation on alternating additive-subtractive hybrid manufacturing of 316L stainless steel thin-walled parts

Abstract

Abstract The additive-subtractive hybrid manufacturing (ASHM) technology has become a research hotspot in recent years. In order to realize high-precision manufacturing of complex parts and avoid machine interference, the alternating additive manufacturing (AM) and subtractive manufacturing (SM) are valuable to be adopted. In this paper, the finite element numerical model was developed to simulate the temperature, stress distribution and deformation of the alternating ASHM thin-walled parts after the AM process and the subsequent milling process. Then, 316L stainless steel thin-walled samples were built by alternating ASHM. In AM process, the molten pool temperature was measured by a colorimetric pyrometer. And the surface contour of the sample was adopted by a laser distance sensor after each AM and SM operation. The results show that higher tensile stress is exhibited at the top and bottom of the AM segments, and the residual stress level decreases after the subsequent milling due to stress relaxation. Moreover, the deformation of the two ends and the top of the AM segments is more significant than that of the bottom. After SM, the deformation of the top of the SM segments is still slightly more extensive than that of the bottom. The next AM segment has little effect on the deformation of the upper SM segment, but has a destructive impact on the interface between the SM and upper AM segment. The repeated cutting height between the SM and upper AM segment was studied. This study may offer valuable guidance for 316L thin-walled parts fabricated by alternating ASHM.