Metal powder might look inert, but it’s chemically reactive, especially to water. Even trace amounts of humidity can alter its behavior during laser melting. Moisture adsorbed on the surface of particles promotes oxidation, reduces flowability, and contributes to spatter, porosity, and inconsistent fusion. For metal AM processes like SLM or DMLS, this translates to real financial risk.
Uncontrolled humidity also affects powder reuse. Each cycle of exposure degrades the powder’s characteristics unless it’s carefully managed. This is why top-tier AM operations use sealed containers, desiccants, and even inert gas storage chambers to keep powder dry between builds. These safeguards maintain consistent rheology and chemistry across multiple cycles.
Failure to control humidity doesn’t just impact print quality, it reduces overall process reliability. You’ll see higher scrap rates, inconsistent microstructures, and dimensional variability. Even worse, these issues might only show up after post-processing or under cyclic stress, making root-cause analysis more difficult and costly.
If you’re investing in metal powder, you’re investing in performance. Protecting that investment with proper environmental controls isn’t optional, it’s part of ensuring build quality, traceability, and repeatability. Humidity control is one of the least expensive, highest-ROI steps in additive manufacturing.