What are the cemented carbide types?
Cemented carbides are a range of composite materials which consist of hard carbide particles bonded together by a metallic binder.The proportion carbide phase is generally between 70~97% of the total weight of the composite and its grain size averages between 0.4um and 10um.
Tungsten carbide(WC),the hard phase together with cobalt(Co),the binder phase,forms the basic cemented carbide structure,from which other types of cemented carbide have been developed.In addition to the straight tungsten carbide-cobalt compositions-cemented carbide may contain varying proportions of titanium carbide(TiC),tantalum carbide(TaC) and niobium carbide(NbC).These carbides are mutually soluble and also can dissolve high proportion of tungsten carbide.Also,cemented carbides are produced which have the cobalt binder phase alloy with,or completely replaced by,other metals such as iron(Fe),chromium(Cr),Nickel(Ni),molybdenum(Mo),or alloys of these elements.
Thus there are three individual phases which make up cemented carbide.In metallurgical terms,the tungsten carbide phase(WC) is referred to as a-phase(alpha),the binder phase(i.e Co,Fe,Ni etc.) as the β-phase(beta),and any other single or combination of carbide phases(TiC,Ta/NbC etc) as theγ-phase(gamma).
Other than for metal cutting applications,there is no internationally accepted classification of cemented carbides.However,the cemented carbide grades developed by Gmond-Hardmetal fall into four main groups as WC-Co grades,corrosion-resistant grades,dual property grades,and grades containing cubic carbides.
The Application Range of Straight Grade of Cemented Carbide
