Direct Energy Deposition (DED)

Direct Energy Deposition builds or repairs metal parts by welding feedstock layer-by-layer, ideal for large features, cladding, and high-value repairs.

Overview

Direct Energy Deposition (DED), also called laser metal deposition or directed energy deposition, uses a focused energy source (usually a laser) to melt metal powder or wire as it is fed into the melt pool, building material onto a substrate. The process runs on multi-axis systems and often on hybrid CNC machines, enabling near-net-shape builds, feature additions, and repairs on existing parts.

DED fits best for large parts, heavy sections, and high-value components where material savings, repairability, or added features matter more than fine detail. It excels at blade and mold repair, wear or corrosion-resistant cladding, and building near-net shapes for follow-on machining. Tradeoffs include coarse feature resolution, relatively poor as-built surface finish, heat input that can drive distortion, and the near-necessity of post-machining on critical surfaces. It shines in low to medium volumes, repair work, and situations where buying a large forging or casting would be expensive or slow.

Common Materials

  • Ti-6Al-4V
  • Inconel 718
  • Stainless Steel 316L
  • Maraging Steel
  • Cobalt-Chrome
  • Aluminum 6061

Tolerances

±0.010" to ±0.020" on as-deposited geometry

Applications

  • Turbine blade tip and edge repair
  • Mold and die repair or feature build-up
  • Wear and corrosion-resistant cladding on shafts and valves
  • Large structural brackets built near-net for post-machining
  • Adding bosses, lugs, or ribs to forgings and castings
  • Functionally graded or multi-material transitions on critical parts

When to Choose Direct Energy Deposition (DED)

Choose Direct Energy Deposition when you need to repair or modify existing metal parts, apply cladding, or build large near-net shapes for later machining. It is well-suited to low-volume, high-value components where material savings, repairability, or design flexibility justify post-processing and looser as-built tolerances. Use it when part size or geometry makes powder-bed metal printing impractical.

vs Laser Powder Bed Fusion (DMLS/SLM)

Pick DED when the part is physically large, needs to be built onto an existing component, or requires high deposition rates instead of fine feature resolution. Use it when you plan to machine back to final dimensions and care more about buy-to-fly ratio and repair capability than small wall thickness and intricate details.

vs Electron Beam Melting (EBM)

Choose DED when you need to work outside a vacuum chamber, build onto existing hardware, or integrate the process on a machine tool for hybrid manufacture. It is better suited for repair, cladding, and on-part build-ups where loading a full build plate into a vacuum system is impractical.

vs Binder Jetting (Metal)

Select DED when you need fully dense, structural metal in a single step without sintering, or when you must add material to an existing part. It is preferable for repairs, thick sections, and critical load paths, while accepting coarser resolution and slower throughput on small features.

vs CNC machining

Use DED over pure machining when the buy-to-fly ratio is high and you would otherwise hog most of a forging or plate into chips. It is effective for building near-net shapes, then finish-machining only what is needed, or for adding localized material to extend life on expensive machined components.

vs Casting

Choose DED when tooling cost or lead time for a new casting is prohibitive, or when you need to iterate geometry quickly. It is also attractive for repairing or upgrading existing castings with added features or improved local properties instead of replacing the entire part.

Design Considerations

  • Design critical features with extra stock for post-machining; specify machining allowances on drawings so vendors can plan finishing operations
  • Avoid very thin walls and fine lattice features; target minimum wall thickness in the 2–3 mm range for stable deposition
  • Model realistic access for the deposition head and shielding gas; check that all build regions are reachable in planned orientations
  • Limit overhangs to roughly 45° from vertical or provide build-up features that allow stable layer stacking without unsupported melt pools
  • Clearly define repair or cladding zones on the CAD and drawing, including depth of build, substrate material, and any dissimilar material interfaces
  • Call out critical datums and tolerance zones that must be machined after DED, and relax tolerances on purely as-deposited, non-critical regions