When people think of additive manufacturing, many conjure up an image of high-intensity laser beams melting shapes into a bed of thinly layered metal powder. While this is the best and most appropriate method for many types of products and parts, it's only one of many that additive manufacturers have at their disposal. To decide on which is the best method, you have to start at the end: whatever the part or product's final application will be.
When designing parts and finished products for additive manufacturing, there are methods used that lend themselves to certain materials and application requirements. Here's a list of 10, designed to explore each technique as well as relevant pros and cons.
SLA- Stereolithography
Popular for creating finely detailed shapes. Liquid photo-polymers are heated into semi-liquid form, then formed into shapes layer by layer, hardening on contact during the construction.
DLP- Digital Light Processing
The oldest and most economical 3D printing technology. Similar to SLA for its ability to handle photopolymers. Very common in prototyping. DLP uses arc lamps instead of Ultra Violet Light to harden the processed plastic. Results in much faster print times, while still delivering high resolution models.
FDM- Fused Deposition Modeling
A popular technology for creating functioning prototypes, proof-of-concept models, and manufacturing jigs and fixtures. Very accurate detailing, and exceptional strength to weight ratio.
SLS- Selective Laser Sintering
A 3D printing machine powder bed is lowered incrementally through the laser scanning process. Un-sintered powders are used to help support the structure during the build, eliminating the need to design support structures in the part. It’s a fast, high-quality process that is perfect for end-use, functional parts and prototypes.
SLM- Selective Laser Melting
Using a high-powered laser beam, this process melts and fuses various metallic powders together. The main diff erence between SLS and SLM, is that SLS only partially melts the powder, where SLM melts the powder completely. SLM products tend to have fewer or no voids, producing a stronger component. This process is especially useful for 3D parts that have complex structures, geometries and thinner walls.
EBM- Electron Beam Melting
Given the broad spectrum of conditional tolerances required by most aerospace components, DMA testing characterizes a material’s properties, such as stiff ness, as a function of temperature, time, frequency, stress, or atmosphere.
Wire Arc Additive Manufacturing
Unlike the more common metal powder AM processes, Wire Arc Additive Manufacturing works by melting metal wire using an electric arc as the heat source. The wire, when melted, is then extruded in the form of beads on the substrate. As the beads stick together, they create a layer of metal material. The process is then repeated, layer by layer, with a robotic arm, until the metal part is completed. unlike the more common metal powder AM
LOM- Laminated Object Manufacturing
A rapid prototyping system, this process uses heat and pressure to cut a fused material (laminated layers of plastic or paper). A new laminated sheet is rolled out and cut again by the laser nozzle. Despite it’s unpopularity as a test process, LOM is one of the fastest and most aff ordable rapid prototyping systems in existence.
BJ- Binder Jetting
Using a powder-based material and a bonding agent, the printer nozzles extrude the binder in liquid form. After each layer is finished, the build plate lowers the distance equivalent to the thickness of a new powder layer that is swept over the entire fixture.
MJ- Material Jetting
Also known as wax casting, this process is used to produce high-resolution parts, mostly for dental and jewelry industries. No post-curing is needed, but a gel is used to provide support during the layering of more complex geometries. Once cleaned, the parts are completely ready to go – no further post-curing is needed.
Want to find out more? Check out our Additive Manufacturing Testing & Analysis Page.
