Direct Energy Deposition (DED) is a series of several similar metal 3D printing technologies that creates parts by melting and fusing material as it is deposited. While it can be used to manufacture new parts, DED is typically used for repairing and rebuilding damaged components. One of the main metal 3D printing technologies, DED is already utilized in key industries like aerospace & defense, oil & gas, as well as the marine industry. In today’s tutorial, we’ll explore the DED process, its benefits and limitations and existing use cases.
How does DED work?
Direct Energy Deposition sometimes goes by several different names, including 3D laser cladding and directed light fabrication. Additionally, certain proprietary technologies modelled on DED are sometimes used interchangeably: Electron Beam Additive Manufacturing (Sciaky), Laser Engineered Net Shaping (Optomec), Rapid Plasma Deposition (Norsk Titanium) or Wire Arc Additive Manufacturing. Although each process works slightly differently, the principle behind them is the same.
In the DED process, the feedstock material, which comes in either metal powder or wire form, is pushed through a feed nozzle where it is melted by a focused heat source (most commonly a laser, but could also be an electron beam or arc) and successively added onto the build platform. Both the heat source and feed nozzle are mounted on a gantry system or robotic arm. The process typically takes place in a hermetically sealed chamber filled with inert gas to better control the material properties and protect the material from unwanted oxidation.
Direct Energy Deposition Pros
DED additive manufacturing has been in use for a number of years now and offers a range of benefits:
- Ideal for repairing parts: The ability to control the grain structure of a part makes DED a good solution for the repair of functional metal parts.
- High printing speed: Typically, DED machines have high material deposition rates. For example, some DED processes can achieve a speed of up to 11 kg of metal per hour.
- Multi-material capabilities: With DED, powders or wires can be changed or mixed during the building process to create custom alloys. The technology can also be used to create a gradient between two different materials within the same build, achieving stronger material properties for a part.
- High-quality metal parts: DED produces highly dense parts with mechanical properties as good as or better than those of comparable cast or wrought materials. Parts produced with DED can also reach near-net shapes, meaning that they will require little post-processing.
Limitations of DED?
Some of the limitations of DED include:
- Low resolution: Parts produced with Direct Energy Deposition tend to have low resolution and poor surface finish, thus requiring secondary machining which will add time and cost to the overall process.
- Cost: DED systems are typically very expensive, with costs exceeding $500,000.
Common use cases
DED has been successfully applied in various industries, including aerospace, oil & gas, defense, marine and architecture. Aerospace manufacturers are increasingly using the technology to produce structural parts for satellites and military aircraft.
In addition to metal additive manufacturing machines and producing metal parts, DED technology is well-suited for repairing damaged parts. Thanks to the strong metallurgical bond and fine, uniform microstructures DED can produce, components like turbine blades and injection molding tool inserts can be reconditioned. By repairing worn parts, molds or dies, DED allows significantly reducing downtime and costs associated with part’s replacement whilst extending the life of the part.
Furthermore, DED can be used to modify parts. For example, by using the technology to deposit a wear resistant hard-facing layer, wear and corrosion resistance of a part can be improved.
The future of DED
DED offers numerous advantages for industries that require the creation or efficient repair of high-value equipment and bespoke metal parts, especially those of a larger size. Looking into the future, we expect the scope of applications for the technology to expand, particularly due to the exciting trend of hybrid manufacturing. Through its integration with conventional manufacturing technologies, DED could bring advances to industries on the lookout for innovative and cost-effective production opportunities.