Metal 3D printing, or ALM, is used to produce complex and one-piece metal parts with geometries that are impossible to machine. This is an ideal 3D printing technology for your complex metal parts: lighter parts and high-performance materials.
For your metal parts production needs, majority uses two metal fusion or ALM (Additive Layer Manufacturing) technologies: laser (DMLS®) and electron beam (EBM). Metal fusion, also commonly known as metal 3D printing, presents definite advantages to conquer new markets.
Additive Manufacturing (AM) is an appropriate name to describe the technologies that build 3D objects by adding layer-upon-layer of material, whether the material is plastic, metal, concrete or one day…..human tissue.
Common to AM technologies is the use of a computer, 3D modeling software (Computer Aided Design or CAD), machine equipment and layering material. Once a CAD sketch is produced, the AM equipment reads in data from the CAD file and lays downs or adds successive layers of liquid, powder, sheet material or other, in a layer-upon-layer fashion to fabricate a 3D object.
The term AM encompasses many technologies including subsets like 3D Printing, Rapid Prototyping (RP), Direct Digital Manufacturing (DDM), layered manufacturing and additive fabrication.
AM application is limitless. Early use of AM in the form of Rapid Prototyping focused on preproduction visualization models. More recently, AM is being used to fabricate end-use products in aircraft, dental restorations, medical implants, automobiles, and even fashion products.
While the adding of layer-upon-layer approach is simple, there are many applications of AM technology with degrees of sophistication to meet diverse needs including:
+ a visualization tool in design
+ a means to create highly customized products for consumers and professionals alike
+ as industrial tooling
+ to produce small lots of production parts
+ one day….production of human organs
Some envision AM as a complement to foundational subtractive manufacturing (removing material like drilling out material) and to lesser degree forming (like forging). Regardless, AM may offer consumers and professionals alike, the accessibility to create, customize and/or repair product, and in the process, redefine current production technology.
Whether simple or sophisticated, AM is indeed AMazing and best described in the adding of layer-upon-layer, whether in plastic, metal, concrete or one day…human tissue”.
Some Examples of Additive Manufacturing (AM)
Very high end technology utilizing laser technology to cure layer-upon-layer of photopolymer resin (polymer that changes properties when exposed to light). The build occurs in a pool of resin. A laser beam, directed into the pool of resin, traces the cross-section pattern of the model for that particular layer and cures it. During the build cycle, the platform on which the build is repositioned, lowering by a single layer thickness. The process repeats until the build or model is completed and fascinating to watch. Specialized material may be needed to add support to some model features. Models can be machined and used as patterns for injection molding, thermoforming or other casting processes.
Process oriented involving use of thermoplastic (polymer that changes to a liquid upon the application of heat and solidifies to a solid when cooled) materials injected through indexing nozzles onto a platform. The nozzles trace the cross-section pattern for each particular layer with the thermoplastic material hardening prior to the application of the next layer. The process repeats until the build or model is completed and fascinating to watch. Specialized material may be need to add support to some model features. Similar to SLA, the models can be machined or used as patterns. Very easy-to-use and cool.
Multi-Jet Modeling is similar to an inkjet printer in that a head, capable of shuttling back and forth (3 dimensions-x, y, z)) incorporates hundreds of small jets to apply a layer of thermopolymer material, layer-by-layer.
This involves building a model in a container filled with powder of either starch or plaster based material. An inkjet printer head shuttles applies a small amount of binder to form a layer. Upon application of the binder, a new layer of powder is sweeped over the prior layer with the application of more binder. The process repeats until the model is complete. As the model is supported by loose powder there is no need for support. Additionally, this is the only process that builds in colors.
Somewhat like SLA technology Selective Laser Sintering (SLS) utilizes a high powered laser to fuse small particles of plastic, metal, ceramic or glass. During the build cycle, the platform on which the build is repositioned, lowering by a single layer thickness. The process repeats until the build or model is completed. Unlike SLA technology, support material is not needed as the build is supported by unsintered material.
3D Printing, or Additive Manufacturing as it less popularly but perhaps more accurately known, is the process of building up objects layer-by-layer, adding material as you go. Its emergence as a tool not only for prototyping, but also functional applications (e.g., replacement parts, tooling) and production parts (that commonly wouldn't be achievable any other way).
Selectively melting powdered material with a focused energy source - a laser or electron beam. This is the most accurate of metal printing technologies before post-processing, allowing tolerances potentially tighter than 50µm. Powder Bed Fusion technology also offers tremendous geometric flexibility, including the ability to fabricate "no assembly required" parts with "captured" sub-assemblies that are held in place by unmelted powder until it is removed in post-processing. It is generally best for parts under a 300mm in the X, Y, or Z dimension, although sizes up to 450mm in a given dimension are possible for select materials.
The process of spraying an adhesive binder onto powdered material to build up a part, sintering the part in a furnace, and infiltrating that "green" part with a lower melting temperature metal. Binder Jetting with Metal Infiltration is most commonly done with a stainless steel matrix infiltrated with bronze (see picture above). Very cost effective but not as high accuracy (tolerances on the order of 1%-3%), Binder Jetting with Metal Infiltration is a great option for complex, traditionally cast geometries (e.g., jewelry).
Jetting powdered metal into a melt pool created by a focused energy source. Directed Energy Deposition is a very fast process relative to other technologies, with a rapid deposition and melting rate. The tradeoff is lower as-built tolerances; design files should typically be provided assuming a 200 micron overbuild to be removed in post-processing. Because it does not operate as a powder bed, Directed Energy Deposition (DED) is ideal for part repair applications and adding features to existing parts. Additionally, its faster deposition rate makes it a viable option for ground-up building of larger parts, up to 2500 mm in a single dimension.
Sheet Lamination involves laying down sheets of metal foil on top of one another, using vibration and tremendous weight to create a bond between the layers, then cutting away excess material. This metal 3D Printing process does not require heat, making it uniquely suited for embedded sensors. Additionally, because foil sheets can be readily traded in and out during the fabrication process, dissimilar laminates can be used, making it an intriguing fabrication option for heat exchanger parts.
Metal Extrusion involves a heated nozzle processing metal beads housed in a polymer jacket. The nozzle melts the polymer jacket just enough to lay the material down on the build platform, layer by layer. The "green" parts are then placed in a furnace where the polymer material burns off, leaving a ~95%-97% dense sintered metal part.
Similar to Binder Jetting with Metal Infusion, this process involves spraying an adhesive binder onto powdered metal beads, layer-by-layer, to build up a part. Once the "green" part is built, the part is placed into a furnace where the adhesive is burned off, leaving a dense part. This process is best for smaller parts, as shrinkage of the green part in post-processing creates challenges with larger geometries.