What Is Additive Manufacturing?
Additive Manufacturing is the process of creating near net 3D dimensional shapes by adding material successively adding material. Additive Manufacturing is traditionally broken down into two forms. Plastic Additive Manufacturing and Metal Additive Manufacturing.
Plastic Additive Manufacturing
Finding the Right Technology
Additive Manufacturing first began with Stereolithography (SLA) which was patented in 1984 with the first production SLA units being manufactured by the newly founded 3D Systems. Stereolithography is done using a basic CNC machine with light curable resins cured by an servo adjusted scanning mirror and lens assembly. This unit traces the pattern of the layer at the top of the liquid then moves to allow a new thin layer of liquid to flow over top and repeats the process.
Fused deposition modeling followed close behind in 1988 when a husband a wife tried to make a frog model with a glue gun. They realized that when this process was controlled by a 3 axis CNC machine they could control the extrusion rate and location creating fused deposition modeling and Stratasys .
Selective Laser Sintering (SLS)
Was patented for the first time in 1979 but was not pursued commercially until 1990's. This system uses a sintering laser to heat the material to temperatures below there melting point of liquefaction. When each layer is complete a recoater arm covers the part with a new layer of powder.
Metal Additive Manufacturing
A World of Possibilities
Direct Metal Laser Sintering
Direct Metal Laser Sintering shared its development with with Selective Laser Sintering. This type of machine uses a fiber or CO2 Laser to sinter the layer. Then a recoater arm will apply and smooth a new layer of powder then the process is repeated.
Wire Base Additive
Wire based additive is likely one of the most diverse groups of technology currently available within the additive realm. The basis of this group of technology is that it uses existing MIG welding spools in combination with an arc welding or electron beam system to fully melt each layer.
Electron Beam Melting
Electron Beam systems utilize a vacuum chamber with an electron gun that is amplified and directed by focus and deflection lenses to create temperatures in excess 1000 °C. This can fully melt most materials creating a solid and dense part at the end of the process.