GB/T 37561-2019Standard practice for de-agglomeration of refractory metal powders and their compounds prior to particle size analysis (English PDF)

Foreword

This Standard was drafted in accordance with the rules given in GB/T 1.1-2009.

1 Scope

This Standard specifies standard practice for de-agglomeration of refractory metal powders and their compounds prior to particle size analysis.

This Standard applies to the practice for de-agglomeration of refractory metals such as tungsten, molybdenum, niobium, tantalum and tungsten carbide and compound powders. Other metal powders (or carbides, nitrides) can also refer to this Standard for de-agglomeration practice.

2 Normative references

The following documents are indispensable for the application of this document.

For dated references, only the dated version applies to this document. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 19077, Particle size analysis. Laser diffraction methods

3 Method summary

3.1 Place the powder to be de-agglomerated in a grinding bottle of a certain specification; place in an appropriate amount of grinding rod; place on a grinding machine; perform grinding under certain conditions. Under the action of the shear force, the agglomerated particles are dispersed into the original particles, without causing excessive cracking of the particles.

3.2 This method can be used for sample preparation of GB/T 3249, GB/T 13390,

GB/T 19077, GB/T 21779 and other practices of particle size analysis. However, this method shall not be used if there is no requirement for the particle size (grinding state and supply state).

Note: This method does not guarantee that the powder particles will not be broken when grinding and de-agglomerating; some particles will still be broken. However, this method provides a reliable de-agglomerating effect. […]