GB/T 3249-2009

This standard specifies the test method for determining the Fisher number (average particle size) of metal powders and related compounds using the Fisher Sub-Sieve Sizer. It is applied in the metallurgy industry for quality control and specification verification of powders used in powder metallurgy, additive manufacturing, and the production of cemented carbides. The method is particularly relevant for characterizing powders with particle sizes in the sub-sieve range (typically 0.2 to 50 micrometers) to ensure consistent flowability and compaction behavior.