Composition and cleanliness
A powder specification begins with alloy chemistry and limits for relevant impurities. Oxygen, carbon and contamination can influence processing and finished properties. The required controls differ between ferrous, copper-based and reactive alloy systems.
Size and shape
Particle size distribution describes a population, not one ideal particle. Morphology and surface condition influence packing and handling. A fine powder for moulding and a powder selected for die compaction may have very different requirements.
Flow and packing
Flow behaviour, apparent density and other process-related measurements help describe how a powder behaves in equipment. Test method and conditions matter; results should be interpreted alongside the route for which the powder is being qualified.
A specification belongs to an application
A useful technical enquiry identifies the intended process, material family, required properties and validation needs. This gives the powder producer and component developer a common basis for setting the material specification.