State of the Art in Directed Energy Deposition: From Additive Manufacturing to Materials Design

TLDR

Additive manufacturing is a new paradigm for designing and producing high‑performance components across aerospace, medical, energy, and automotive sectors. The review aims to comprehensively survey directed energy deposition additive manufacturing, covering system classification, process variables, physics, modelling, defects, mechanical properties, quality control, and practical process mapping for diverse materials, while highlighting emerging applications. The authors analyze DED systems by classifying equipment, detailing process variables and physics, reviewing modelling approaches, identifying common defects, assessing mechanical properties, and developing a process map based on linear heat input and powder feed rate, with discussion of emerging applications. The review identifies three under‑optimized DED regions—lack of fusion, keyholing, and mixed‑mode porosity—and recommends future research to advance the technology from form to function for industrial benefit.

Abstract

Additive manufacturing (AM) is a new paradigm for the design and production of high-performance components for aerospace, medical, energy, and automotive applications. This review will exclusively cover directed energy deposition (DED)-AM, with a focus on the deposition of powder-feed based metal and alloy systems. This paper provides a comprehensive review on the classification of DED systems, process variables, process physics, modelling efforts, common defects, mechanical properties of DED parts, and quality control methods. To provide a practical framework to print different materials using DED, a process map using the linear heat input and powder feed rate as variables is constructed. Based on the process map, three different areas that are not optimized for DED are identified. These areas correspond to the formation of a lack of fusion, keyholing, and mixed mode porosity in the printed parts. In the final part of the paper, emerging applications of DED from repairing damaged parts to bulk combinatorial alloys design are discussed. This paper concludes with recommendations for future research in order to transform the technology from “form” to “function,” which can provide significant potential benefits to different industries.