Tungsten Carbide (WC-Co) — Materials Encyclopedia Entry

Cemented tungsten carbide is a powder-metallurgy composite of tungsten carbide (WC) grains bonded by a cobalt (Co) matrix. It is the standard material for industrial blades that face abrasive substrates, high-impact events, or very long service intervals.

Composition: Tungsten carbide (WC) grains 80–95 % by weight; cobalt binder 5–20 % by weight. Optional grain-growth inhibitors (TaC, NbC, Cr₃C₂) for sub-µm grades.

ISO 513 classification: K-series (cast iron, non-ferrous metals, non-metallics). K05 (3 % Co, fine grain, finishing) through K40 (20 % Co, coarse grain, primary shredders).

Hardness: HRA 86–93 (roughly HRC 73–83 equivalent). Higher Co = lower hardness, higher toughness.

Properties: Wear resistance 8–15× HSS at the same application. Toughness lower than HSS (fracture toughness K_IC 8–15 MPa·√m for 6–15 % Co grades). Density 14.5–15.5 g/cm³ (vs 8.1 for HSS).

Applications: Granulator bed and rotor knives, recycling shredders, stainless plate shear inserts, corrugated slitter scorer blades, abrasive non-woven slitters. Standard material for any industrial blade that needs > 10× the wear life of D2.

Common grades (GB / ISO): YG6X (K10–K20, 6 % Co fine grain, slitter); YG8 (K20–K30, 8 % Co, granulator); YG10X (K30, 10 % Co fine grain, impact-loaded granulator); YG15 (K30–K40, 15 % Co, recycling).

See also: YG6X vs YG8, HSS vs Carbide, Material Grade Converter.