Influencing factors of cemented carbide density

       

If you don't understand the density of cemented carbide and the influencing factors, it is easy to make mistakes in choosing cemented carbide. The following briefly introduces the density of cemented carbide and its influencing factors.

Density is the mass per unit volume, and is usually referred to as the ratio of the density (specific gravity) mass m to the volume v of a material. It uses the drainage method to measure density, and its calculation formula is as follows: p=m/v, the unit is kilogram per cubic meter (kg/m3).

The density of cemented carbide, material composition, porosity, and carbon content have a great relationship. The density of cemented carbide is extremely sensitive to the composition and porosity when the composition is certain.

Density is closely related to the content of material components. For example, the density of tungsten-cobalt alloy decreases as the content of cobalt increases.

Density is also closely related to the size of the pores. The presence of pores and the size of pores directly affect the density of cemented carbide. Due to the existence of pores, the actual density is less than the theoretical density. Carburizing, underburning, dirtying, bubbling, peeling, and not being compacted during the pressing and sintering process of cemented carbide will cause its density to decrease.

Density and carbon content: In the case of constant composition and pores, the density of cemented carbide has a direct relationship with the eta phase and free carbon in the cemented carbide. In the WC+у+η three-phase region, as the carbon content decreases, the η phase increases, and Co decreases, and the W content in the у phase increases, and the density increases. In the WC+у+η three-phase region, as the amount of carbon increases (free carbon is called "C" type pores), the density decreases. In the WC+у two-phase region, as the carbon content decreases, the W content in the у phase increases and the density increases. In general, if the carbon content of normal tissue increases by 0.1 to 0.13%, its density decreases by 0.1g/cm3. The density of tungsten carbide (WC, also abbreviated as TC) is 15.7 g/cm3, and the density of cobalt is 8.9 g/cm3.

Density is usually used in the cemented carbide industry to determine the correctness of a grade's composition. Different from the usual understanding, the porosity level of modern cemented carbide cannot be determined by the method of measuring density. The density of tungsten carbide (WC) is 15.7 g/cm3, and the density of cobalt is 8.9 g/cm3. Therefore, for WC-Co grades, with the increase of cobalt content, the density decreases linearly. The increase of titanium carbide leads to a decrease in density, because the density of pure titanium carbide is only 4.9. The density of tungsten carbide (WCWC, also abbreviated as TC) is 15.7 g/ cm3, the density of cobalt is 4.9 g/cm3.

Therefore, when choosing tungsten steel materials, it is best to have a basic understanding of the material's hardness, bending strength, density and other physical properties and scope of application.