Deformation Prediction and Experimental Study of 316L Stainless Steel Thin-Walled Parts Processed by Additive-Subtractive Hybrid Manufacturing

Abstract

The hybrid process integrates two or more different processes, such as additive and subtractive manufacturing, which have gained appreciable consideration in recent years. The deformation of hybrid manufacturing is an essential factor affecting machining quality. The purpose of this paper is to study the effect of milling on stress release and surface deformation of additive manufacturing (AM) specimens in the process of additive and subtractive hybrid manufacturing (ASHM) of 316L stainless steel thin-walled parts, so as to effectively improve the forming quality of thin-walled parts manufactured by the combined processing of ASHM. To this end, a series of experiments were carried out to study the relationship between stress distribution and thermal stress deformation of 316L stainless steel thin-walled parts prepared by LMD, and the changes of stress and deformation of these thin-walled parts after subsequent milling. An infrared camera and laser distance sensor were used to record the temperature field data and deformation data to analyze the influence factors of temperature and stress on the machining results. Then, the finite element software was used to simulate the stress and deformation of the thin-walled parts in the additive manufacturing process and the subsequent milling process. Meanwhile, the model was verified through the experiments. In addition, the relationship between the milling force and the milling parameters of the AM parts was studied by orthogonal test and regression analysis.

Measuring and Predicting the Effects of Residual Stresses from Full-Field Data in Laser-Directed Energy Deposition

“…Note, here, that the estimated values of the thermal expansion coefficient are close to 17.62 C, the value that was previously reported in [ 30 ].…”

“…The material used for this study is AISI 316L stainless steel with Young’s modulus 138 GPa and Poisson’s ratio 0.29. The thermal expansion coefficient, being a stochastic variable, is chosen from a uniform distribution with lower limit equal to the one of conventional steel (10.5 C) [ 29 ] and upper limit the one corresponding to L-DED-processed AISI 316L stainless steel (17.62 C) [ 30 ]. The bottom layer (green) is constructed using the same elastic properties but very low thermal expansion coefficient, resulting in a ‘stiff’ (with respect to temperature changes) material.…”

316L Stainless Steel Thin-Walled Parts Hybrid-Layered Manufacturing Process Study

“…The particle size ranges from 75 to 150 µm, and the powder has good flowability and thermal processing properties. The chemical composition of the powder is shown in Table 1 [16]. The substrate material used in the melt deposition forming experiment is a 316L stainless steel rolled steel plate with dimensions of 250 × 150 × 15 mm.…”

“…Additive/Subtractive Hybrid Manufacturing (ASHM) is an emerging manufacturing technology that combines the advantages of Additive Manufacturing (AM) and traditional Subtractive Manufacturing (SM) [14,15]. This technology relies on Laser Metal Deposition (LMD), which combines AM and SM and can produce parts with complex geometries, as well as good surface finish and dimensional accuracy [16]. In ASHM-based Selective Laser Melting (SLM), after the scanning laser beam forms multiple powder layers, the milling cutter machines the finished parts, and the next SLM process begins.…”

Combined manufacturing and cost complexity scores-based process selection for hybrid manufacturing

“…Thin walls and gaps are highly affected by thermal deformations due to a fixed size nozzle. 1,29 The definition of two threshold values G min and W min is recommended to ensure the machining of all gaps and walls in each layer. Commonly, G min and W min must be higher than four times the layer thickness in FDM.…”