tungsten carbide EDM-block

About the hardness of tungsten carbide

Tungsten carbide hardness is measured by a testing instrument such as the Rockwell hardness tester or Brinell hardness tester.
Cemented carbide’s hardness ranges from HRA75 to HRA95, and varying hardness levels are appropriate for diverse working circumstances.
How is carbide hardness related to its composition?
It is evident that cemented carbide’s hardness is linked to the cobalt (nickel) binder’s content (%). Generally, the HRA hardness of Cemented Carbide tends to decrease as the content of binder cobalt (or nickel) increases.

Relationship between cobalt content and hardness

At the same time, there is a relationship with the grain size of tungsten carbide, the main component of cemented carbide, the finer the grain size μm, the higher the hardness and the better the wear resistance of cemented carbide made from tungsten carbide powder.

Different hardness of carbide is suitable for different working conditions.
For example
Fine grain tungsten carbide + low cobalt <10% carbide is suitable for making cutting tools, end mills, non-impact wear parts, seal rings, etc. Medium grain tungsten carbide + medium cobalt amount >10-15% carbide is suitable for making stamping dies, drawing dies, etc.
Coarse grain tungsten carbide + high cobalt amount >20% carbide is suitable for manufacturing mining tools, rolls, impact resistant parts.
The application of carbide grades cannot be simply distinguished by hardness and needs to be evaluated by professional technical engineers.
Professional mechanical structure design can make carbide have longer service life.

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by YATECH MATERIALS

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