Directed Energy Deposition (DED)
Directed Energy Deposition
• Directed Energy Deposition
• Steps to perform
• Types of Directed Energy Deposition
• Materials
• Advantages and Disadvantages
• Applications
Additive manufacturing technologies: rapid prototyping to direct digital
manufacturing, Ian Gibson, David W. Rosen, Brent Stucker, Springer, 2010.
AM Processes Classification
As per ASTM F42, AM processes are classified into 7 catagories
1) Vat Photopolymerisation
2) Material Jetting
3) Binder jetting
4) Material extrusion
5) Powder bed fusion
6) Sheet lamination
7) Directed energy deposition
Directed Energy Deposition (DED)
• Directed Energy Deposition (DED) is a more complex AM process, typically used to repair or add additional
material to existing components. It is completely possible to fabricate parts from scratch using this technology,
but it is often used for industrial applications such as repairing turbine blades or propellers that have been
damaged.
• Similarly to some Powder Bed Fusion (PBF) technologies (such as LPBF or EBM), Directed Energy Deposition
uses a focused energy source, such as a laser or electron beam or Arc to melt the material. However, the
material is melted at the same time as it’s deposited by a nozzle. In a way, the technology is at the frontier of
material extrusion and powder bed fusion.
Directed Energy Deposition (DED)
Directed Energy Deposition (DED)
Directed Energy Deposition (DED)
Directed Energy Deposition (DED)
Overview
• Creation of parts by melting and deposition of material from powder or wire feedstock. –Similar to FDM
• Energy beam focused into a narrow region, which is used to heat a material that is being deposited.
• Unlike the powder bed fusion techniques discussed earlier, DED processes are NOT used to melt a material that is pre-
laid in a powder bed but are used to melt materials as they are being deposited.
Directed Energy Deposition (DED)
Variants : one medicine, many bottles
Electron Beam
• Laser Engineered Net Shaping (LENS) Electron Beam Freeform Fabrication (EBF3)
• Directed Light Fabrication (DLF)
• Direct Metal Deposition (DMD)
• 3D Laser Cladding Arc
Laser
• Laser Generation • 3D Welding
• 3D Welding and Milling
• Laser-Based Metal Deposition (LBMD)
• WAAM
• Laser Freeform Fabrication (LFF)
• HLM
• Laser Direct Casting • PAAM or PAM
• HPAM
• LaserCast
• Laser Consolidation
Directed Energy Deposition (DED)
General Deposition Process Description for Components
Laser
• Deposition head
–laser optics,
–powder nozzle(s),
–inert gas tubing
–and in some cases, sensors.
• Substrate
–either a flat plate on which a new part will be fabricated
–or an existing part onto which additional geometry will be added.
Process
• The laser generates a small molten pool (typically 0.25–1 mm in diameter and 0.1–0.5 mm in depth) on the substrate
• Powder is injected into the pool.
• The powder is melted as it enters the pool and solidifies as the laser beam moves away.
Directed Energy Deposition (DED)
Material Delivery
• Powder Feeding
• Wire Feeding
Directed Energy Deposition (DED)
Powder vs Wire
Directed Energy Deposition (DED)
Processes based on Energy Source Used
• Laser-based Deposition Processes
–LENS, LAM, POM+Trumpf
• Electron Beam Based Deposition Processes
–Electron Beam Freeform Fabrication (EBF3)
• Arc-Based Deposition Processes
–3D Welding of Nottingham Univ, SDM, KIST, SMU, IITB, IITH etc.
Directed Energy Deposition (DED)
Lasers
• Laser Engineered Net Shaping (LENS): Developed by Sandia National Laboratories, marketed by OptoMec
• Laser Additive Manufacturing (LAM): Developed by AeroMet Corp. Mainly for large parts and Ti.
• Direct Light Fabrication (DLF): Developed by Los Alamos National Laboratory. Uses CNC tool-path format.
• Laser Based Additive Manufacturing (LBAM): Developed by Southern Methodist University. Includes real-time sensing of the process.
• Direct Metal Deposition (DMD): Developed at University of Michigan. Includes closed-loop control and generation of melt pool.
• Rapid Direct Metal Deposition using wire feed instead of powder delivery. Developed by Korea Institute of Science and Technology
(KIST).
Directed Energy Deposition (DED)
Lasers
Arc
Electron Beam
• 3D Welding
• 3D Welding and Milling
• 3D Micro Welding (3DMW)
• Hybrid Layered Manufacturing (HLM)
• Hybrid Plasma Deposition and Milling (HPDM)
• Shape Deposition Manufacturing (SDM)
Directed Energy Deposition (DED)
Deposition Systems using GMAW
Directed Energy Deposition (DED)
Laser/Electron Beam vs. Arc
LAM (laser)
LENS (laser) DLF (laser) Arcam (EB)
HLM (arc)
Directed Energy Deposition (DED)
Laser/Electron Beam vs. Arc
• Hybrid Approach is inescapable to achieve the desired quality
• Laser and Electron Beam also used to build near-net shapes
• HLM uses Arc based weld-deposition
Directed Energy Deposition (DED)
Shape Deposition Welding
• Shape Deposition Manufacturing (SDM) does not use conventional slicing; in fact, it is ‘segmenting’ rather than
‘slicing’.
• SDM is based on the premise that the invisible surface of the model will be the visible surface of the support and vice-
versa. If the model is visible, model is made; if the model is invisible, support is made. This way, model and support
materials are created alternately. The creation of model or support involves deposition and machining. So it is a hybrid
process.
• Its slicing makes use of visibility concepts. Therefore, the part is free from staircase effect. Its order matches with the
original geometry.
• The deposition creates the near-net shape fast and 5 axis CNC machining is used for net-shaping it. It also makes use of
shot-peening for metal prototypes to relieve the stresses.
• Like FDM, this also uses two heads, one for model and the other for support.
• A variety of deposition methods are used. A variety of materials are attempted.
• However, we shall focus more on its metallic applications.
Shape Deposition Welding
Deposition Methods
• In order to make prototypes of various material, the following methods are used for the
deposition:
–extrusion
–2-part resin systems
–hot wax dispenser
–Photo-curable dispenser
–Micro-casting
–welding
–thermal spraying
• The last three are for metals. They are all variations of welding processes.
Shape Deposition Welding
Steps
• In other processes such as FDM, the modeling material and support material will be deposited only once per
layer. Unlike this, in SDM, the model and support materials may be deposited alternately within the same
layer so that at any time, the region of deposition is free from undercuts. Each such deposition of model or
support material is followed by 5 axis machining. 3 axis machining also will do!
Shape Deposition Welding
Steps
Shape Deposition Welding
Step 1
Step 2
Step 3
Shape Deposition Welding
Advantages & Limitations
Advantages:
• Fewer slices due to the use of adaptive slices of highest order edge.
• Slicing is based on manufacturability rather than accuracy requirement.
• Metallic/ non-metallic parts/ tools can be made.
• Finds applications in MEMS etc.
• Functionally graded and composite products.
Limitations:
• Not fully automatic.
• For metallic parts, copper as support material is not satisfactory. While copper is being dissolved by Nitric acid, the part
also is pitted considerably.
Materials and Applications of DED
• Metals can be 3D printed through the DED additive manufacturing technique and notably include aluminum,
copper, titanium, stainless steel, tool steel, copper nickel alloys, and several steel alloys. Each sub-technique of
the Directed Energy Deposition section has its own limitations and compatibilities.
• It is true that this process is typically used with metals, in the form of either powder or a wire. However, it is
possible to use DED with polymers and ceramics too. For example, AREVO uses Polymer DED with a filament of
carbon fiber to fabricate lightweight composite parts for end use applications.
• The thermoplastic filament is melted by a heat source and compacted by a roller to generate the layers of the
object. They can also be categorized further based on the lamination technique used to bond the sheets together,
such as adhesive bonding, thermal bonding and ultrasonic welding. There are also variations in when they are
formed.
Materials and Applications of DED
• For metals, almost any metal that is weldable can be 3D printed with DED. That includes titanium and titanium
alloys, inconel, tantalum, tungsten, niobium, stainless steel, aluminium, etc. The wire used typically ranges from
1-3 mm in diameter and powder particle sizes are similar to those used in powder metallurgy processes,
between 50 and 150 microns.
• As previously mentioned, one of the unique applications of this technology is that it is possible to repair metal
parts that have been damaged. According to ASTM International: “DED has the ability to produce relatively large
parts (build volume > 1000 mm³) 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.”
Materials and Applications of DED
• Predominantly, DED uses metal in the form of either wire or powder. However, DED technology is also capable
of using polymers and ceramics. For example, Arevo makes composite frames using polymer and filament of
carbon fibre.
• DED supports a wide range of metals as any metal that can be welded can be used to create parts through this
technology. Commonly used materials by various manufacturers are as follows;
Titanium and Titanium alloys Niobium
Inconel 718, 625 Stainless Steels (300 series)
Hastelloy Aluminium alloy 2319, 4043
Tantalum Zinc alloy
Tungsten Copper-Nickel alloys
Materials and Applications of DED
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 65 735 x 650 x 560 mm
Advantages
• DED technologies are used exclusively in metal additive manufacturing due to the nature of the process and
are ideally suited for repairing or adding material to existing components.
• High build rates – DED’s higher deposition rates at relatively low resolution means faster build rate compared
to some other metal additive manufacturing process
• Dense and strong parts – DED creates higher density parts hence their mechanical properties are as good
as cast or wrought material
• Near net shape – Parts can be near net shapes requiring minimal amount of post-processing
• Can be used for repairing – Ideally suited for application requiring metal addition to existing parts hence
lends itself for repairing applications
Advantages
• Multi-material range – Latest DED machines have the capability to have several different powders or wire
containers which enables to build parts with custom alloy
• Larger parts – Comparably larger parts can be built using DED. For example, Sciaky’s EBAM printers have the
capability to print parts a few meters high
• Easy material change – Since the material is fed during the process on demand from separate powder
containers, it’s easy to refill or change the material
• Reduced material waste – DED only deposits the material it needs during the process meaning less wastage
compared to processes like powder bed fusion (SLS and DMLS) where, the full build platform has to be filled with
metal powder
Disadvantages
• High capital cost – Direct energy deposition systems are comparably very expensive to the other types
of metal additive manufacturing systems
• Low build resolution – Parts produced using DED technology are lower in resolution with a poor surface
finish. It will look like sand or investment castings and would require secondary processing such as
machining or aqua blasting, hence adding more time and cost
• No support structures – Due to its nature of how the DED technology builds parts, support structures
cannot be used during the build process, hence features like overhangs will not be possible
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.
Typical direct energy deposition applications
• DED is already utilized in key industries like aerospace, defense, oil & gas, as well as the marine industry, for
example, aircraft frames and structures, refractory metal components, ballistic material tooling repair and
reconditioning and marine propulsion, etc.
• Like any other subtractive manufacturing process, parts made using DED can be heat-treated, hot-isostatic-
pressed, machined, or finished in any customary manner, which opens various new applications. Most of the
hybrid manufacturing systems use DED and have increased in popularity.
Thank You!
