EBM Ti-6Al-4V

EBM runs at ~700 °C build chamber temperature and uses an electron beam in vacuum. The pre-heat eliminates almost all residual stress (no plate warping, no post-build stress-relief), and build rates are 2–3× L-PBF on the same Ti volume.

Pick EBM for large monolithic Ti structures, dense build plates, and orthopedic implants where porous lattice surfaces are a design feature.

• Build volumes > 1000 cm³
• Patient-specific orthopedic implants
• Parts where residual-stress distortion has been a recurring issue

Surface finish is Ra 20–35 µm vs L-PBF's 6–15 µm. Minimum wall is ~0.8 mm vs L-PBF's 0.4 mm. The coarser melt pool also limits the smallest printable feature to ~0.6 mm.

Fatigue allowables sit slightly below L-PBF for the same condition, dominated by surface roughness. Machine the fatigue-critical surfaces and the gap closes.

No stress-relief is needed — the elevated chamber takes care of it.

• Powder removal: blast in a PRS
• HIP: 920 °C / 100 MPa / 2 h
• Surface: machine critical features; chemical mill for general finish
• Optional: alpha-case removal if any open-air post-bake occurred

GE Additive Arcam Q20+ starting recipe at 70 µm layer.

• Layer thickness: 70 µm
• Beam current: 15 mA
• Scan speed: 4500 mm/s
• Pre-heat: 700 °C chamber
• Vacuum: < 5 × 10⁻⁴ mbar