When to pick AlSi10Mg
AlSi10Mg is the AM equivalent of a near-eutectic cast aluminum. It prints reliably, has the best thermal conductivity in the L-PBF aluminum family (~130 W/m·K), and welds for assembly.
Pick it for housings, heat exchangers, and topology-optimized brackets up to ~150 °C service temperature. For higher temperature or higher strength, look at Scalmalloy or A20X.
Defects and post-processing
AlSi10Mg is prone to hydrogen porosity (0.5–1.5 %) and benefits from HIP. The as-built microstructure is fine-cellular and gives surprisingly good as-built strength; T6 raises UTS by ~10 % at the cost of ductility.
ForgeCast applies a conservative fatigue band — published AM AlSi10Mg fatigue scatter is the highest of any qualified metal AM material.
Suggested parameters
Starting recipe on a 400 W Yb-fiber machine at 30 µm layer.
- Layer thickness: 30 µm
- Laser power: 350 W
- Scan speed: 1400 mm/s
- Hatch spacing: 190 µm
- Pre-heat: 150–200 °C plate (reduces cracking)
- Atmosphere: argon, O₂ < 100 ppm
Frequently asked questions
Should I run T6 or use the as-built parts?
T6 buys ~10% UTS but cuts elongation roughly in half. For static-load housings and heat exchangers, as-built + stress-relief is often the better trade.
Why is fatigue so much lower than wrought 6061?
Hydrogen porosity, surface roughness, and the fine cellular structure all push AM aluminum fatigue down by ~30–50% vs forged wrought equivalents. HIP and surface machining close most of that gap.
Sources
- EOS AlSi10Mg material datasheet
- ASTM F3318 — AM AlSi10Mg
- NIST AM Bench AlSi10Mg benchmark series