Powder Handling Process
We recognize the critical nature of the powder feedstock in our systems, both from a quality and safety perspective, which is why the MetalFAB is designed to eliminate exposure of powder particles to both oxygen moisture and human contact.
Powder materials can be kept in inert conditions directly from the atomizer and using the Additive Industries Powder Load Tool (PLT) loaded and unloaded directly to and from the system. The system ensures that powder is constantly kept under controlled conditions and no operator contact is necessary via its integrated powder sieving/transportation system and automated powder extraction procedure.
The system is compatible with industry standard powder particle size distributions. Details on our powder specifications can be found here:
Our systems are compatible with industry standard powder particle size distributions which we specify to ensure the robustness and repeatability of our process parameters and consistency and quality of the parts our systems produce.
Our powder specifications are set to ensure all powders:
- Are of the correct chemical composition
- Minimise sources of degradation such as moisture
- Flow freely: correct morphology and particle size distribution
- Maintain a long life in the system
Particle Size Distribution (PSD):
PSD is a key part of ensuring powder flowability, and our systems work with various ranges depending on material type –typical PSD ranges for our technology are in the 15-45μm or 20-63μm ranges. It is important for the process to have a distribution of fine and coarse particles to ensure packing in the powder bed and flowability of the powder – this is a sensitive balance and incorrect distribution can lead to poor flowability or entrapped gas porosity.
Morphology:
This is another measure which represents the flowability of powder, relating to the shape of the particles and usually measured qualitatively by SEM and/or quantified by measuring the aspect ration of the powder.
Moisture:
Moisture has a direct impact on powder flowability – generally powders with high moisture content will not flow well whilst also cause quality issues to arise where moisture is released during the process providing a source of oxidation and Hydrogen pickup. This is why the Additive Industries approach to material control using our PLT is so critical to part quality.
Production Methods:
Additive Industries systems process powders produced through either gas atomization or plasma atomization technique.
