Tool grades

Micro-grain cemented carbide



Micro-grain cemented carbide is, as the name explains, cemented carbide that is composed of very fine WC particles. Cemented carbides with WC particles under 1μm in diameter are termed as micro-grain cemented carbides.

In general, the main components are WC-Co cemented carbide with a small amount of VC (vanadium carbide) and Cr3C2 (chromium carbide). The chromium carbide is added as a particle growth inhibitor*. This is to prevent the particles from growing during the sintering process.


The mechanical properties of micro-grain cemented carbides are high hardness and transverse rupture strength (TRS). The graph tp the right shows a comparison between micro-grain cemented carbide and general cemented carbide. It shows that when micro-grain cemented carbide and general cemented carbide posses the same hardness, the micro-grain cemented carbide has a higher TRS value.

The graph above shows the relationship between hardness - and TRS (transverse rupture strength).

Likewise, if the micro-grain cemented carbide and general cemented carbide have the same TRS value, then the micro-grain cemented carbide is harder than the general cemented carbide. This is all due to the fine grain structure. When the carbide particles are fine, the amount of Co between WC particles becomes less and this improves the plastic deformation resistance (hardness). Additionally as the grains become smaller, crack propagation is inhibited leading to higher fracture resistance (transverse rupture strength).


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