Directed Energy Deposition (DED)
Directed Energy Deposition, or DED, is most commonly used in the 3D printing of metal, but can also be used in polymers and ceramics. DED machines typically consist of a deposition head mounted on a multi axis arm above a build platform. The arm moves around the platform and the head expels a stream of metal powder (or other material). A high-powered laser then melts the material upon deposition. In the case of metals, a shielding gas is used to allow solidification without the threat of oxidation. Additional material is then added, layer by layer, to create a new object or repair an existing one. To that end, an emerging niche for DED lies in part repair where new material is added to an existing part that has failed in service.
Powder Bed Fusion (PBF)
Also known as SLS, or Selective Laser Sintering, this technology is widely used in both metals and polymers. PBF systems use a laser to melt layers of material powder and then fuse them together. Typical PBF machines consist of a laser, a build platform, a reservoir to hold fresh material powder, and a powder roller (or in some cases, a blade). The roller distributes a layer of material powder from the reservoir, across the build platform. The laser then melts and fuses the first layer of the object. The build platform lowers and the roller spreads a new layer of material powder over the original fused layer. The laser melts and fuses the second layer of material to the first, and the process continues until the object is fully realized. Any unfused material powder that remains is later removed during post process. Objects printed using PBF tend to be more accurate than parts printed using DED, however DED is typically faster. Additionally, PBF parts are typically better suited for visual models and prototypes, as many of the materials used in this process lack structural properties.
Fused Filament Fabrication (FFF)
Often known by its tradename, Fused Deposition Modeling, or FDM, this technical category is most commonly used in plastics and polymers. FDM machines push material (typically in spool form) through a heated nozzle that moves along two axes above a build platform. Like most 3D printing techniques, FDM builds an object layer by layer. It differs however, in that the material is constantly under pressure as it is fed at a constant rate through the heated nozzle. The build platform lowers with each new layer, and these layers are then bonded to previous layers via temperature control or chemical agents. FDM has the benefit of being relatively inexpensive as most materials used for this technique are easily accessible. However, FDM tends to be among the slower forms of 3D printing, and due to the nozzle radius, can also be one of the least accurate.
These core technologies behind 3D printing have helped to usher in an unprecedented era of rapid prototyping to the manufacturing industry. And still, the future looks even brighter. With the pool of materials expanding to offer more capabilities and to fit more applications; with more advanced forms of 3D printing technologies coming into the fold, such as jetting, that allows for faster, more accurately built parts; 3D printing is sure to be a key driver for the future of the manufacturing industry.
At Panova, we make it our business to follow and understand these advances so that we can properly advise and guide our clients. We’ve enabled our clients to experience the benefits of 3D printing first hand, as we’ve employed our in-house 3D printers to aid in the product design and development of many custom components. Our printers have allowed us to reduce their projects’ needs for part revisions and engineering hours, and have greatly increased the rate at which we develop and deliver their products.
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