About Cemented Carbide (I)

1.The Main Component of Cemented Carbide
Cemented carbide is made of high-hardness, refractory metal carbide (WC, TiC) micron powder as the main component, with cobalt (Co), nickel (Ni), and molybdenum (Mo) as the binder. It can be used in a vacuum furnace or hydrogen Powder metallurgy products sintered in a reduction furnace.
For example:

2.The Compose of the substrates of cemented carbide
The substrates of cemented carbide is composed of two parts: one part is the hardening phase, and the other part is the bonding metal.
The hardened phase is the carbide of transition metals in the periodic table, such as tungsten carbide, titanium carbide, and tantalum carbide. Their hardness is very high, and their melting points are above 2000°C, and some even exceed 4000°C. In addition, transition metal nitrides, borides, and silicides have similar characteristics and can also act as hardening phases in cemented carbide. The existence of the hardening phase determines the alloy has extremely high hardness and wear resistance.
The bonding metal is generally iron group metals, and cobalt and nickel are commonly used.

3.How each component work in manufacturing
When manufacturing cemented carbide, the particle size of the raw material powder selected by the cemented carbide factory is between 1 and 2 microns, and the purity is very high. The raw materials are mixed according to the specified composition ratio, and alcohol or other medium is added to wet grinding in a wet ball mill to make them fully mixed and crushed. After drying and sieving, a molding agent such as wax or glue is added. The mixture is obtained by sieving. Then, when the mixture is granulated and pressed, and heated to close to the melting point of the binder metal (1300-1500°C), the hardened phase and the binder metal will form a eutectic alloy. After cooling, the hardened phase is distributed in the grid composed of the bonding metal, and is closely connected with each other to form a solid whole. The hardness of cemented carbide depends on the hardened phase content and grain size, that is, the higher the hardened phase content and the finer the grains, the greater the hardness. The toughness of cemented carbide is determined by the bond metal. The higher the content of the bond metal, the greater the bending strength.

Post time: Mar-15-2021