Metal 3D Printing — DMLS and SLM Guide

Complete guide to metal additive manufacturing: DMLS vs SLM, materials, design rules, post-processing, and cost factors.

Metal Additive Manufacturing

Metal 3D printing builds parts layer by layer from metal powder using a laser or electron beam.

DMLS vs SLM

DMLS: Sinters powder below melting point. 95-98% density.

SLM: Fully melts powder. 99.5-99.9% density, matching wrought properties.

Materials

• Ti6Al4V (Titanium) — Aerospace, medical implants
• AlSi10Mg (Aluminum) — Automotive, heat exchangers
• 316L Stainless — Marine, chemical processing
• Maraging Steel — Ultra-high strength tooling
• Inconel 718/625 — Turbine, rocket engine parts

Design Rules

• Minimum wall: 0.3-0.5 mm
• Overhangs: 45 degree rule — supports below 45 degrees
• Layer height: 20-100 μm
• Powder removal: minimum 2 mm internal channels

Post-Processing

Nearly all parts need: support removal, stress relief/HIP, surface finishing, heat treatment. Post-processing can equal build cost.

Cost

Build time $50-200/hour, powder $50-400/kg. Best for low-volume complex parts (1-100 units).