Cemented carbide tools, as the name implies, are made of cemented carbide with extremely high hardness. This material has the advantages of high strength, good toughness, wear resistance and corrosion resistance, and is widely used in cutting.
1. Titanium carbide
At high temperature, it reacts with oxygen to form titanium oxide (Tic), aluminum oxide and other substances to form metal TiC2. Because TiC2 is a refractory intermetallic compound and presents solid state, it is also called sintered titanium carbide or sintered titanium nitride (TICN).
Due to the low melting point, high density, poor thermal conductivity, strong impact resistance and other characteristics of carbide, it has many advantages as a blade material:
(1) High temperature resistance
Because the carbide crystal structure is dense and hard, it is not easy to soften and deform at high temperature; In addition, due to the small coefficient of thermal expansion, its heat-resistant temperature range is wide; At the same time, due to its high hardness and good wear resistance, it is not easy to collapse and damage during high-speed cutting.
(2) Good corrosion resistance
The surface of carbide crystal has a very thin oxide protective layer and has certain chemical resistance. Therefore, it can prolong the service life and reduce the wear rate when it is used to manufacture blades. In addition, because of its good oxidation resistance, thermal stability and certain mechanical strength and other comprehensive properties, it can be used for processing in various media, such as: stainless steel, cast iron, copper and other metals.
(3) High strength
It can be seen from the above that the carbide crystal structure is dense, hard and dense, so it has high strength and toughness; At the same time, its low thermal conductivity also makes its heat dissipation conditions better, thus improving its rigidity and impact resistance; In addition, it is not easy to soften and deform at high temperature, which makes it one of the good tool materials.
(5) Easy to weld
Because titanium carbide is solid granular crystal, it is easy to be formed by powder metallurgy production and can be made into thin sheets for welding and forming. In addition, due to its low melting point and a small amount of volatile components, the melting temperature is greatly reduced and thus easy to weld.
2. Cobalt-based cemented carbide
Cobalt-based cemented carbide can be divided into two categories, namely cobalt-based coated cemented carbide and uncoated cemented carbide. The difference between uncoated cemented carbide and cobalt-based cemented carbide is mainly in heat treatment.