A Novel Method for Additive/Subtractive Hybrid Manufacturing of Metallic Parts

TLDR

Additive manufacturing enables complex part fabrication but suffers from lower dimensional accuracy and surface quality compared to conventional machining, limiting its industrial use. The study develops and evaluates an additive/subtractive hybrid manufacturing process for 18Ni maraging steel, aiming to improve part quality by combining selective laser melting with precision milling. The hybrid process uses selective laser melting followed by precision milling, with subsequent material characterization via XRF, XRD, SEM, and hardness testing. The results offer a practical guide for selecting process parameters in additive/subtractive hybrid manufacturing.

Abstract

Additive Manufacturing (AM) has been developed for industrial applications due to its superior capabilities, such as building complicated parts that are otherwise difficult to manufacture by the conventional methods. However, the dimensional and geometric accuracies as well as surface quality of an AM produced part are inferior to the conventionally machined part, which hinders the AM applications. A novel additive/subtractive hybrid manufacturing (A/SM) method is developed to take advantage of both simplex AM and precision milling. The method combines the selective laser melting with precision milling for improved surface finish as well as geometric and dimensional accuracies of a part. This study presents the research outcomes of A/SM of an 18Ni maraging steel part, analyzes its microstructure and hardness variations, and compares it with those made by the simplex AM and other methods. The study also deals with material characterization with X Ray Fluorescence (XRF), X-ray diffractometry (XRD), scanning electron microscopy (SEM), and hardness measurement. The study provides a valuable guide for determining the A/SM process parameters.