Metal 3D printing: What is Direct Energy Deposition?
Direct Energy Deposition (DED) refers to several similar metal 3D printing technologies that create parts by melting and fusing material. While it can be used to produce new parts, DED is also typically used to repair and rebuild damaged components. As one of the most important metal 3D printing technologies, DED is already being used in key industries such as aerospace, oil and gas, and marine. In today's tutorial, we will explore the DED process, its benefits and limitations, and existing use cases.
How does DED work?
Direct Energy Deposition (DED) is often referred to by various names, including 3D laser cladding and Directed Light Fabrication. In addition, certain proprietary technologies modeled after 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 starting material, which is either in metal powder or wire form, is forced 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 an electric arc). and added to the build platform one at a time. Both the heat source and the feed nozzle are attached to a gantry system or robotic arm. The process typically takes place in a hermetically sealed chamber filled with inert gas to better control material properties and protect the material from unwanted oxidation.
Materials for Direct Energy Deposition
DED supports a wide range of metals, including:
- Titanium alloys
- Stainless steel
- Maraging steels
- Tool steels
- Aluminum alloys
- Refractory metals (tantalum, tungsten, niobium)
- Superalloys (Inconel, Hastelloy)
- Nickel Copper
- Other special materials, composites and functionally graded materials
Remarkably, the materials used in DED are considerably cheaper than the metal powders used in powder bed machines.
Direct energy capture: advantages and disadvantages
DED technology has already been in use for several years and offers a number of advantages:
Ideal for repairing components: The ability to control the grain structure of a part makes DED a good solution for repairing functional metal parts.
Larger 3D printed parts: Unlike powder metal AM processes, which typically produce smaller, high-definition parts, some proprietary DED processes can produce larger metal parts - for example, Sciaky's proprietary Electron Beam Additive Manufacturing (EBAM) technology is said to be able to produce parts larger than 6 meters in length.
High pressure speed: Typically, DED machines have high material deposition rates. For example, some DED processes can reach speeds of up to 11 kg of metal per hour.
Less material waste: As SLM and DMLS processes distribute powder on the build platform and then selectively fuse it together, a lot of unmelted powder can often be left behind that needs to be reused. In processes with DED, only the required amount of material is processed. As there is no waste powder to recycle, this leads to efficient material consumption and cost savings.
Multi-material capabilities: With DED, powders or wires can be altered or mixed during the build process to create customized alloys. The technology can also be used to create a gradient between two different materials within the same build job, achieving stronger material properties for a part.
High quality metal parts: DED produces high-density parts with mechanical properties that are as good as or better than those of comparable cast or wrought materials. Parts produced with DED can also take near-net-shape forms, which means they require little post-processing.
Hybrid manufacturing capabilities: DED is one of the few metal 3D printing technologies that can be integrated into machining centers to create a hybrid manufacturing solution. By mounting an application nozzle on a multi-axis machining system, highly complex metal parts can be produced faster and more flexibly.
What are the limits of the DED ?
The restrictions of the DED include:
Low resolution: Parts produced with Direct Energy Disposition have low resolution and poor surface finish, requiring post-processing that adds time and cost to the overall process.
No support structures: DED is not suitable for creating support structures, which restricts the production of parts with certain geometries, e.g. overhangs.
Cost: The cost of DED systems is usually very high, in excess of 500,000 US dollars.
Direct Energy Deposition: Machines & Manufacturer
In the table below, we have summarized the main companies that have developed proprietary technologies based on the DED process, together with the available machines and their build volumes.
| Manufacturer | System name | Build volume |
| Sciaky | EBAM® 68 | 711 x 635 x 1600 mm |
| EBAM® 88 | 1219 x 89 x 1600 mm | |
| EBAM® 110 | 1778 x 1194 x 1600 mm | |
| EBAM®150 | 2794 x 1575 x 1575 mm | |
| EBAM® 300 | 5791 x 1219 mm x 1219 mm | |
| Optomec | LENS 450 | 100 x 100 x 100 mm |
| LENS MR-7 | 300 x 300 x 300 mm | |
| LENS 850-R | 900 x 1500 x 900 mm | |
| LENS 860 Hybrid | 860 x 600 x 610 mm | |
| BeAM | Modulo 250 | 400 x 250 x 300 |
| Modulo 400 | 650 x 400 x 400 | |
| Magic 800 | 1200 x 800 x 800 | |
| InnsTek | MX-600 | 450 x 600 x 350 mm |
| MX-1000 | 1,000 x 800 x 650 mm | |
| MX-Grande | 4,000 x 1,000 x 1,000 mm | |
| DMG Mori (Hybrid) | LASERTEC 65 3D | 735 x 650 x 560 mm |
Frequent use cases
DED has been successfully used in various industries including aerospace, oil & gas, defense, marine and architecture. Aircraft manufacturers are increasingly using this technology to produce components for satellites and military aircraft. Lockheed Martin Space, for example, recently qualified Sciaky's EBAM process to build titanium fuel domes for satellites. By using the technology, the company was able to reduce the production time for the component by 87% and cut the lead time from two years to three months.
DED is also being considered for structural parts for commercial aircraft. One example is recently FAA-approved airplane engine parts for Boeing's 787 Dreamliner, manufactured by Norsk Titanium. The Norwegian company utilized its proprietary Rapid Plasma Deposition technology, a form of DED technology that resulted in a significant improvement in the buy-to-fly ratio compared to conventional manufacturing methods. Now that titanium parts are going into production, Boeing expects to reduce production costs per airplane by 2 to 3 million US dollars.
In addition to the production of metal parts, DED technology is ideal for repairing damaged parts. Thanks to the strong metallurgical bond and the fine, uniform microstructure that DED can produce, components such as turbine blades and injection mold inserts can be reconditioned. By repairing worn parts, molds or dies, DED allows for a significant reduction in downtime and costs associated with part replacement while extending the life of the part.
In addition, DED can be used to modify parts. For example, the wear and corrosion resistance of a part can be improved by using the technology to build up a wear-resistant hard coating layer.
The future of DED
Direct Energy Deposition offers numerous advantages for industries where high-value devices and customized metal parts, especially those with larger dimensions, need to be manufactured or efficiently repaired. Looking to the future, we expect the applications for the technology to expand, particularly due to the exciting trend of hybrid manufacturing. By integrating with conventional manufacturing technologies, DED could make progress in industries looking for innovative and cost-effective production options.