Additive Manufacturing:

Classification by Material

  • Powder Bed Fusion (PBF): laser or Electron Beam to melt and fuse powder

  • Material Extrusion (MEX): involves extruding a heated filament through a nozzle

  • Vat Photopolymerization (VPP): vatof liquid polymer resin cured using light

Classification by Energy

  • Direct Energy Deposition (DED): energy melts and deposits material directly onto platform

  • Binder Jetting (BJ): binders put onto powder bed to find particles, then separate infiltration

Types of Powder Bed Fusion

  • Powder Bed Diffusion (PBF): uses heat source to melt and fuse powder layer by layer

    • Qualities: accuracy, surface finish, compatibility; challenging with traditional Manufacturing

  • Selective Laser Sintering (SLS): Heats material just below melting point to make strong bonds

    • Qualities: deals with plastics, high accuracy, versatile

  • Direct Metal Laser Sintering (DMLS): same as SLS, uses mirror to direct laser

    • Qualities: uses metallic powder instead of plastic

  • Electron Beam Melting (EBM): high power Electron Beam in vacuum for metal powders

    • Qualities: enhancing metallic properties for alloys, special

Material Extrusion Process

  • Continuous Filament Extrusion: continuous filament material fed through heated nozzle, LBL

  • Fused Deposition Modeling (FDM): uses spool of thermal plastic filament, LBL

Vat Photopolymerization Techniques

  • Stereolithography (SLA): that containing liquid resin and UV laser beam

    • Advantages: laser accuracy, fast, dimensional stability

  • Digital Light Processing (DLP): Software converts data into image layer projected onto surface of resin vat by high res projector utilizing DMD

    • Qualities: gives stair stepping effect

Direct Metal Deposition

  • Direct Metal Deposition: uses laser to melt and fuse metal powder particles, LBL

    • Qualities: High precision, versatility Of metal spool

  • Electron Beam Additive Manufacturing (EBAM): high-powered Electron Beam within a vacuum, works best with high density specialized alloys

Inkjet and Binder Jetting Techniques

  • Inkjet Deposition: use printer head Jets droplets of liquid material onto powder bed, no binding agent

  • Binder Jetting: Utilizes a powder bed and binding agent to construct 3D objects (adhesive)

    • Binder Jetting Process: prep powder bed, binder jet, layer recoating, repeat, part infiltration, post-process

Stair-Stepping Effect

  • Description: rigid stairs due to depositing discreet layers

  • Minimize: reduce layer height, adjust printing orientation, post-processing technique

Supports

  • Purpose: prevent overhangs from collapsing or deforming during printing, can be made from same material as part or different

  • Types:

    • Point Supports: touching model

    • Branch Support

    • Raft Support: below model

Post-Processing and Finishing

  • Processes: support removal, cleaning, surface preparation