ForMatter/Processes/additive/DMLS / SLM Metal 3D Printing
proc_dmls_metal_3d_printing

DMLS / SLM Metal 3D Printing

additive · DMLS, Direct Metal Laser Sintering, SLM, Selective Laser Melting, powder-bed laser-fusion (PBF-LB)

Metal 3D printing by laser — a high-power fiber laser scans across a thin layer of metal powder, fully melting the cross-section of a part one layer at a time. Builds dimensional metal parts directly from CAD with internal cavities and lattice geometries that no other process can produce. The aerospace, medical-implant, and high-performance jewelry-prototyping default for the last 15 years.

Powder-bed laser-fusion (PBF-LB/M) per ISO/ASTM 52900. Workflow: 30–80 µm metal-powder layer recoated, 200–1000 W fiber laser scans pre-determined toolpath at 800–4000 mm/s under inert atmosphere (Ar or N₂), full melting and re-solidification produce fully-dense (≥99.5%) part. Stress-relief heat treatment standard post-build. Build envelope 100–800 mm cube depending on machine class. Supported powders include Ti-6Al-4V, 17-4 PH, AlSi10Mg, IN718, IN625, CoCr, 316L, precious metals (Au, Pt) for jewelry.

Scale & Tolerance

  • scale (mm)0.5 – 800
  • tolerance (mm)0.1
  • skilladvanced — DfAM (design for additive) literacy, support-strategy knowledge, and powder-handling safety all required
  • min skillexpert
  • whereprofessionalindustrial
  • costhigh per part; capital cost very high

Equipment

  • school_shoprare — capital and consumable cost typically out of school-shop range
  • professionalEOS / SLM Solutions / 3D Systems / Renishaw machine in dedicated facility with powder-handling protocol
  • industrialproduction-grade machine with multi-laser scanning, integrated post-processing, and qualified powder supply chain

Environmental

  • energy_usehigh (laser + chiller + atmosphere)
  • waste_streamspent powder (partially recyclable), filtered fines (HazWaste, especially Ti)
  • consumablesargon / nitrogen, virgin powder makeup, filter media

Cost over volume

1101001k10k100k1M0.00010.0010.010.1110100100010000100000units (log scale)total cost (relative, log scale)

Numbers are relative ratios, not dollars. The crossover point matters more than the magnitude. Anchored to injection molding + ABS = 1.0.

Trade-offs

constraints · what is lost · what is gained
Titanium Grade 5 (Ti-6Al-4V)
  • constraints
    • min wall thickness ~0.4 mm at competitive build orientation
    • overhangs >45° need support structures (and post-removal labor)
    • stair-stepping on near-horizontal surfaces — visible at the layer line
    • internal channels need powder-evacuation paths to extract trapped powder
  • what is lost
    • as-printed surface is matte gray, gritty (Ra 6–15 µm); polishing required for clean Ti finish
    • support contact points leave witness marks that need post-machining
    • near-isotropic mechanical properties but visible build-direction texture
  • what is gained
    • lattice / topology-optimized geometry impossible by any subtractive process
    • internal cooling channels and conformal heat-exchanger geometry
    • the canonical aerospace / orthopedic Ti6Al4V process — printed implants, bracket replacements, jet-engine fuel nozzles

Plain language. Neutral framing — perfection is contextual, defined by use. Cf. Winchester, The Perfectionists (HarperCollins, 2018).

Second life

reversibilityzero — laser-fused metal powder is committed.
output recyclabilityyes
waste streams
  • unbound metal powder (95%+ recovered and reused, with some sieve-rejection of degraded particles each cycle)
  • support-structure scrap (CNC-removed and re-melted)
  • inert-gas (argon, nitrogen) consumption
repair compatible withproc_cnc_milling, proc_tig_welding

ASTM ISO/ASTM 52900; EOS / SLM Solutions / Renishaw additive-manufacturing technical literature.

Citations

Further reading