Which additive manufacturing technique uses a laser to fuse materials in a powder form?

The correct answer is Selective Laser Sintering (SLS), which is an additive manufacturing technique that employs a laser to selectively fuse powdered materials together. In SLS, a laser beam scans across a bed of powder, heating it to just below its melting point, causing the particles to fuse and form a solid structure. This layer-by-layer approach allows for the creation of complex geometries and intricate designs that are often difficult to achieve using traditional manufacturing methods.

The other methods and their operational principles differ significantly from SLS. Fused Deposition Modeling (FDM) utilizes filament material that is heated and extruded through a nozzle, making it quite different from the powder-based process of SLS. PolyJet Printing involves jetting liquid photopolymers that are then cured with UV light, focusing on resin instead of powders. Laser Metal Deposition (LMD) does use laser technology but primarily for adding material to an existing structure by melting and depositing metal powders—this is more similar to welding than the sintering process employed by SLS. Each of these methods has unique applications and material uses, but it is SLS that specifically uses a laser to fuse powder materials into solid parts.