Surface residual stresses in additive/subtractive manufacturing and electrochemical corrosion

Abstract

Hybrid manufacturing approaches with additive and subtractive manufacturing is a promising technology for many sectors from personal care goods to aerospace. When it comes to the residual stresses, there are hardly about the additive manufacturing (AM). Although some researches have been conducted for the hybrid laser additive manufacturing and subtractive manufacturing (SM) processes, only the machining parameters, material properties, and surface quality were analyzed; there were a few experiments about the residual stresses. Taking this into account, this paper aims to analyze the surface residual stresses in hybrid manufacturing approaches. Additive machining process, electrochemical corrosion, and surface residual stresses testing were described in detail. The main results of the research would be references for the surface residual stresses when 316L stainless steel specimens are manufactured with laser metal deposition and milling after AM immediately. The oxidation is much serious in additive manufacturing, and the surface tensile stresses are quite small. Both the electrochemical corrosion and milling at high temperature will affect the distribution of the surface residual stresses. The residual tensile stresses are distributed symmetrically after milling process while they are asymmetric after electrochemical corrosion.