Micro-machining of additively manufactured metals: a review

Metal additive manufacturing (MAM) has attracted significant interest in both academia and industry to produce near-net-shape engineering components. The inherent defects in MAM, however, require suitable subtractive techniques as post-processes to control dimensional and geometric tolerances as well as surface finish. The additively manufactured metals, with different microstructures than the wrought materials that produced by conventional routes, need different approaches and parameters when being machined. This review covers recent published literature on traditional micro-machining as a post-processing operation for MAM and recommends future directions. The text presents a brief review on the main AM processes followed by a comprehensive conventional micro-milling and microdrilling, as well as applications for micro-machining. Micro-tool assessment, built-up-edge prediction and prevention, and link of macro/micro-machining are areas for future research.