Factors Affecting Density of Tungsten Cemented Carbide

If you do not understand the density and influence factors of cemented carbide, it will easily lead to the wrong purchase of cemented carbide. The following is a brief introduction of the density and influence factors of cemented carbide.

Density is the mass per unit volume and is commonly referred to as the ratio of the mass (specific gravity) mass m to the volume v of a material. It measures the density by the drainage method and is calculated as follows: p = m / v, the unit is kilograms per cubic meter (kg / m3).

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

There is a close relationship between the density and the content of the material composition. For example, the density of the tungsten-cobalt alloy decreases as the cobalt content increases.

There is also a close relationship between the density and the size of the pores. The presence of pores and the size of the pores directly affect the density of the cemented carbide. Due to the presence of pores, the actual density is less than the theoretical density. The carburizing, underburning, dirtying, bubbling, peeling, unpressing, etc. of the cemented carbide during pressing and sintering will result in a decrease in density.

Density and carbon content: In the case of constant composition and pores, the density of cemented carbide is directly related to the η phase and free carbon in the cemented carbide. In the three-phase region of WC+у+η, as the amount of carbon decreases, the η phase increases, 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 pore), the density decreases. In the WC+у two-phase region, as the amount of carbon decreases, the W content in the у phase increases and the density increases. Under normal circumstances, the normal tissue carbon content increases by 0.1 to 0.13%, and its density is reduced by 0.1 g/cm3. The density of tungsten carbide (WC, also abbreviated to TC) is 15.7 g/cm3, and the density of cobalt is 8.9 g/cm3.

Density is commonly used in the cemented carbide industry to determine the correctness of a grade component. Unlike the usual understanding, the porosity level of modern cemented carbides cannot be determined by measuring the density. The density of tungsten carbide (WC) is 15.7 g/cm3, and the density of cobalt is 8.9 g/cm3. Therefore, for the WC-Co grade, as the cobalt content increases, the density decreases linearly, and the increase in 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.