Cemented carbides represent a group of materials which differ from other hard materials such as ceramics, corundum or diamond in view of their metallic properties.
These metallic properties include for example good electrical and thermal conductivity.
Carbide is a powder-metallurgical two-phase material consisting of a hard material phase and a metal binder phase. The hard material provides the necessary hardness (= wear resistance) and the binder metal guarantees appropriate toughness.
In the case of cemented carbides for cutting tools and wear protection, tungsten carbide (WC) is generally used as a hard carbide phase and cobalt (Co) as metal binder (binder phase). The reason for this is that applying this combination the best physical and mechanical properties can be obtained.
The most important parameters for determination of the carbide properties are the binder content (generally stated as a mass fraction) and the average grain size of the hard material phase.
The classification of carbides according to the WC grain size corresponds to the recommendations of the Powder Metallurgy Association.
In view of the manifold possible combinations of the metal binder content and the grain size, cemented carbide covers a wide range of applications, as can be seen in the following chart.
