Direct Energy Deposition (DED)

Direct Energy Deposition (DED) builds or repairs metal by melting powder or wire in a focused energy beam, suited for large parts and localized features.

Overview

Direct Energy Deposition (DED) is a metal additive process that feeds powder or wire into a melt pool created by a laser, electron beam, or plasma arc, depositing material bead-by-bead onto a substrate or existing part. It excels at adding features to forged/cast/machined preforms, repairing high-value components, and building large structures where a powder-bed machine would be size-limited.

Choose DED when you need controlled, localized buildup, multi-material or gradient capability, or near-net shaping followed by machining. Expect rougher as-deposited surfaces, more thermal distortion risk, and less fine feature resolution than powder-bed processes. Most DED parts require finish machining on critical interfaces, plus post-heat-treat/HIP depending on alloy and performance requirements.

Common Materials

  • Ti-6Al-4V
  • Inconel 718
  • Stainless Steel 316L
  • H13 Tool Steel
  • CoCrMo
  • Aluminum 7075

Tolerances

±0.010" to ±0.030" as-built; ±0.001" to ±0.005" after finish machining

Applications

  • Turbine blade tip repair
  • Mold and die surface build-up
  • Large aerospace structural brackets
  • Valve bodies with hardfaced sealing surfaces
  • Impeller blade repair and rebuild
  • Near-net preforms for finish machining

When to Choose Direct Energy Deposition (DED)

DED fits parts where you want to add material only where needed—repairs, reinforcements, bosses, wear surfaces, or near-net preforms to machine later. It’s strongest on medium-to-large components, low-to-medium quantities, and geometries that don’t demand fine lattice/detail resolution. Plan for post-processing on functional surfaces and for distortion management on thin sections.

vs Laser Powder Bed Fusion (DMLS/SLM)

Choose DED when build size, deposition rate, or adding material onto an existing component matters more than fine detail. DED handles localized buildup and large near-net shapes efficiently, but typically needs more machining because as-built accuracy and surface finish are coarser.

vs Electron Beam Melting (EBM)

Choose DED when you need targeted deposition on a preform/repair or want flexible deposition paths without a powder-bed. EBM is strong for fully dense bulk builds in vacuum and can reduce residual stress for some alloys, while DED is generally better for feature additions and large-area buildup with machining afterward.

vs Binder Jetting (Metal)

Choose DED when you need fully dense material without a sinter/shrink step and when you’re building on an existing substrate or performing repair. Binder jetting can be efficient for higher quantities of small parts, but it relies on sintering/HIP and dimensional change; DED is more direct for large parts, one-offs, and engineered buildups.

Design Considerations

  • Model a clear machining allowance on all critical surfaces (often 0.020–0.060 in depending on bead size and distortion risk).
  • Avoid thin walls and knife edges; keep sections robust to manage heat input and reduce warping and lack-of-fusion risk.
  • Call out deposition areas explicitly (faces/volumes) for repair or feature-add builds; ambiguous “build up as needed” drives cost and scrap risk.
  • Specify substrate material and heat treatment condition; mismatches change dilution, cracking risk, and final properties.
  • Use generous radii and smooth transitions between deposit and base material to reduce stress concentration and improve deposition stability.
  • Provide datum strategy for post-machining (fixturing surfaces, reference bores/planes) so the shop can control final tolerances efficiently.