The Main Properties of Cemented Carbide

Hard alloy is a kind of high hard and brittle material which is composed of refractory metal carbide such as tungsten carbide powder or titanium carbide powder and bonded metal such as cobalt nickel or iron. It has excellent physical and mechanical properties, and has special properties in density, hardness, bending strength, coercive magnetic force, wear resistance, thermal rigidity and toughness. Hard alloy has been widely used in mining, metallurgy, mold, metal processing industry, mainly used to make cutting tools, drilling tools, drilling tools, measuring tools, wear-resistant parts and other products. Zhuzhou Union Hardmetal specializes in the production of carbide products, providing carbide tool solutions to meet customer needs.

1. Density

Density is a measure of mass in a particular volume and is equal to the mass of the object divided by the volume. The density of tungsten-cobalt cemented carbide is 14.4~15.3g/cm3, which generally decreases with the increase of cobalt content. The density of tungsten-cobalt-titanium cemented carbide is 9.7~13.2g/cm3, which generally decreases with the increase of cobalt and/or titanium carbide content. In addition, when the chemical composition of the material is constant, the density of the alloy will decrease with the increase of the voids. Density was measured using the drainage method (Archimedes' law).

2. Hardness

Hardness refers to the ability of alloy material to resist other hard objects pressing into it and causing sag deformation. The hardness of cemented carbide is generally 86 ~ 93HRA (equivalent to 69 ~ 81HRC). When the chemical composition or raw material ratio is different, the hardness of the alloy is different, for example, YG6 is not less than 89HRA, YG8 is not less than 89.5HRA. Common tests for hardness include Rockwell Hardness (HRA) and Vickers Hardness (HV).

3. Bending strength

The bending strength refers to the ability of alloy material to resist bending without breaking, which is generally evaluated by three-point bending test or four-point test method. The factors that affect the bending strength of cemented carbide include the type of cemented carbide and bonding phase, the content and particle size of cemented carbide complex, sintering process, heat treatment process, microstructure defects and residual stress.

Under certain conditions, the bending strength of cemented carbide decreases with the increase of temperature. It increased with the increase of cobalt content (0-15%). With the decrease of the average size of tungsten carbide increases; The uniformity of tungsten carbide particle size increases with better.

4. Coercive magnetism

Coercive magnetic force refers to the strength of the antimagnetic field which completely demagnetizes the alloy after saturation magnetization. It increases with the decrease of grain size, but decreases with the decrease of grain size after reaching a maximum value. It decreases with the increase of cobalt content. When the temperature rises to overfiring, the coercivity of the alloy will also decrease. Coercive magnetic force measurement methods include coercimeter method DC hysteresis loop method and impact method.

5. Wear resistance

Wear resistance refers to the ability of a material to resist mechanical wear, which can be expressed by the amount of wear or the wear resistance index. The measurement methods include weight loss method, dimension change emphasis method, surface topography measurement method and scoring method. Generally speaking, the higher the carbide content, the better the wear resistance of the alloy.

6. Hot Hardness

Hot Hardness refers to the alloy at a higher temperature, still can maintain high hardness properties. The hardness of cemented carbide can still be maintained at about 60HRC at 900~1000℃.

7. Resilience