5.1 This guide applies to directed energy deposition (DED) systems and processes, including electron beam, laser beam, and arc plasma based systems, as well as applicable material systems.

5.2 Directed energy deposition (DED) systems have the following general collection of characteristics: ability to process large build volumes (>1000 mm³), ability to process at relatively high deposition rates, use of articulated energy sources, efficient energy utilization (electron beam and arc plasma), strong energy coupling to feedstock (electron beam and arc plasma), feedstock delivered directly to the melt pool, ability to deposit directly onto existing components, and potential to change chemical composition within a build to produce functionally graded materials. Feedstock for DED is delivered to the melt pool in coordination with the energy source, and the deposition head (typically) indexes up from the build surface with each successive layer.

5.3 Although DED systems can be used to apply a surface cladding, such use does not fit the current definition of AM. Cladding consists of applying a uniform buildup of material on a surface. To be considered AM, a computer aided design (CAD) file of the build features is converted into section cuts representing each layer of material to be deposited. The DED machine then builds up material, layer-by-layer, so material is only applied where required to produce a part, add a feature or make a repair.

5.4 DED has the ability to produce relatively large parts requiring minimal tooling and relatively little secondary processing. In addition, DED processes can be used to produce components with composition gradients, or hybrid structures consisting of multiple materials having different compositions and structures. DED processes are also commonly used for component repair and feature addition.

5.5 Fig. 1 gives a general guide as to the relative capabilities of the main DED processes compared to others currently used for metal additive manufacturing. The figure does not include all process selection criteria, and it is not intended to be used as a process selection method.