MetalFab 420K

The MetalFab 420K is an SLM 3D printer from Additive Industries with a 420 x 420 x 400 mm build volume.

Specifications

Light Engine: 4 × 1 kW full-field fiber lasers (1070 nm): each covering the full 420×420 mm build area; 4 kW total installed power. Variable beam diameter (VBD) 100–500 µm for resolution vs. deposition rate trade-off.

Optics / Scanner: Four independent galvanometric scanner sets; inline automated laser calibration maintains ≤ 0.05 mm positional accuracy without manual intervention.

Platform: Precision 420×420 mm build platform with module-swap compatibility for the MetalFab automation ecosystem (up to 8 sequential autonomous builds).

Build Volume: 420 × 420 × 400 mm: up to 2.5× productivity versus predecessor.

Calibration

Inline automatic laser calibration: All four lasers auto-corrected by the system; acceptance limit ≤ 0.05 mm: do not skip even for short campaigns.

VBD tuning: 100 µm for contours/details, 500 µm for bulk fill: multi-beam strategy reduces build time by up to 30%.

Gas flow check: Smoke test or visual inspection for laminar flow before start; clean outlet grilles to prevent turbulence.

Common defects

Gas porosity: Spherical pores < 50 µm from wet/gassy powder or excessive energy input: dry the powder, reduce power.

Thermal cracking: In hot zones for CM247LC / MAR-M247: platform preheating 200–500°C + island scanning + HIP.

Balling: Surface spheres from O₂ > 500 ppm or oxidised powder: check gas, replace powder.

Recoater crash: Streaks from warped part: add supports in high thermal-gradient zones.

What it is used for

Aerospace serial components (AS9100): Four 1 kW lasers + inline ±0.05 mm calibration deliver repeatability for Ti-6Al-4V and IN718 parts.

Space propulsion parts: Beta-validated with a US space customer; 8-build autonomous sequence minimises operator intervention.

Medical implants (trabecular structures): VBD 100 µm for thin-wall Ti ELI / CoCr parts with osseointegration surfaces.