AM DfAM Series - The Building Blocks of Directed Energy Deposition Design
Laura Ely, The Barnes Global Advisors
My kids love creating structures with Legos, Duplos, and boxes. Some days they build big houses with simple walls and others detailed spaceships with intricate features. Their block choice dictates the structure they build, or they pick the blocks based on the resolution they desire. Directed Energy Deposition (DED), a family of Additive Manufacturing (AM) processes, is quite similar in that a designer has a set of geometric “building blocks” she can combine to make a structure. The feature resolution is based on the size of the melt puddle and part volume on the size of the motion platform, but I am getting ahead of myself.
First, let us break down this AM process, as we do in TBGA Training, by asking (3) questions:
How is a Layer formed?
The layer is created with the energy coming together at a focused point to create a melt puddle which is propagated to form a bead.
Common motion platforms include robots and gantries; additional degrees of freedom are often added with turn or flip/tilt motion for the part fixture and substrate.
How is Energy applied?
Thermal or kinetic energy is used to convert particles or filament (wire) into a solid layer.
Today we are contemplating Fusion (thermal) DED, where the material is melted. Any compatible heat source and material combination can be used including laser, electron beam, plasma, and arc. Other processes use friction, ultrasonic, or kinetic energy.