Metal Powders for Additive Manufacturing

In additive manufacturing the powder is not an input to the process, it is most of the process.

Flowability, particle size distribution and oxygen content decide whether a layer spreads evenly, and all three change with handling.

Reactivity is the first constraint

Fine titanium and aluminium powders ignite readily, burn at high temperature and react with water, which rules out standard firefighting.

Closed, inerted transfer with controlled oxygen monitoring is the normal design, and conductive, grounded components are mandatory rather than advisable.

Vacuum conveying under inert gas keeps both the operator and the powder out of contact with air.

Protecting powder quality

Each reuse cycle adds oxygen, removes the finest fraction and adds spatter particles from the build chamber.

• Sieve after every build to remove agglomerates and spatter.
• Track cycle count per batch and blend to a defined rule rather than by availability.
• Store under inert gas or controlled dew point, since moisture pickup is fast at these particle sizes.

Operator exposure

Nickel and cobalt-bearing alloy powders carry real occupational exposure limits, and the particle size means deep lung deposition.

Glovebox or contained docking arrangements for machine loading and unloading are chosen for exposure control as much as for powder quality.

Traceability

Aerospace and medical users expect batch-level traceability from the powder lot through every build.

That requirement shapes the handling system: dedicated lines per alloy, documented cleaning between alloys and a records trail that survives an audit.

What to establish before buying equipment

• Alloy list and whether shared equipment is acceptable at all.
• Permissible oxygen and moisture pickup across the handling chain.
• Explosion characteristics of the specific powder, including the fines.
• Reuse policy and the sieving cut that supports it.