Каталог Dormer Pramet фрезерование 2021 - 2022 - страница 204

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HM materials

Carbide Materials (or Hard Materials)

HM MATERIALS

A sintered powder metallurgy substrate, consisting of a metallic carbide composite with binder metal. The most central raw material is tungsten carbide (WC). Tungsten carbide contributes to the hardness of the material. Tantalum carbide (TaC), titanium carbide (TiC) and niobium carbide (NbC) complements WC and adjusts the properties to what is desired. These three materials are called cubic carbides. Cobalt (Co) acts as a binder and keeps the material together. Carbide materials are often characterised by high compression strength, high hardness and therefore high wear resistance, but also by limited flexural strength and toughness. Carbide is used in taps, reamers, milling cutters, drills and thread milling cutters.

PropertiesHSS materialsHM materialsK10/30F (often used for solid tools)
Hardness (HV30)800 – 9501300 – 18001600
Density (g/cm3)8.0 – 9.07.2 – 15.014.45
Compressive strength (N/mm2)3000 – 40003000 – 80006250
Flexural strength, (bending) (N/mm2)2500 – 40001000 – 47004300
Heat resistance (°C)5501000900
E-module (KN/mm2)260 – 300460 – 630580
Grain size (μm)–0.2 – 10.00.8

The combination of hard particle (WC) and binder metal (Co) give the following changes in characteristics.

CharacteristicHigher WC content giveHigher Co content give
HardnessHigher hardnessLower hardness
Compressive strength (CS)Higher CSLower CS
Bending strength (BS)Lower BSHigher BS

Grain size also influences the material properties. Small grain sizes means higher hardness and coarse grains give more toughness.