Experimental investigation on the effect of process parameters in additive/subtractive hybrid manufacturing 316L stainless steel

Selective laser melting(SLM)is an additive manufacturing technology which is suitable for manufacturing metal parts with geometrical complexity and high performance. When geometric accuracy and surface roughness are concerned, it is necessary to carry out a subsequent milling process to obtain desirable characteristics after SLM process. recently, additive/subtractive hybrid machine tools have emerged to harness the merits of SLM process and milling process. However, it is scarce of research covering this kind of hybrid system, and studies are needed to explore the effect of processing parameters on the SLM / dry milling hybrid manufacturing processes. In this paper, 316L stainless steel samples were built by hybrid manufacturing. The effect of laser power (P), scan speed (v), and feed per tooth (f(z)) on densification level, hardness, chip morphology, and surface roughness was investigated. The highest densification level and average hardness level was obtained with P = 270 W and v = 900 mm/s. The milling operations had an effect on the density and hardness of the samples produced by hybrid manufacturing, and the extent of the effect varied depending upon SLM parameters. The morphology of the chips varied with f(z) and was influenced by the sample conditions before milling operations. The surface roughness was determined by f(z), and the lowest surface roughness level was obtained with f(z) = 0.02 mm/tooth in the hybrid manufacturing process. Defects on the milled surface was affected by f(z) and sample conditions concurrently.