Basic knowledge of Tungsten Carbide in detail

Cemented Carbide is known as "industrial teeth", and its application scope is very wide, including engineering, machinery, automobile, ship,military industry and otherindustries. Tungsten carbide industry consumes more than half of the total tungsten consumption. Here we introduce it from its definition, characteristics, classification, usage of several aspects.

1. Definition

Cemented carbide is a kind of combined material composed of refractory metal compounds and bonding metals produced by powder metallurgy. It takes tungsten carbide powder (WC) as the main production material and cobalt, nickel, molybdenum and other metals as the binder alloy, which is not much different from the composition of high specific gravity tungsten alloy. Tungsten alloy is a kind of alloy with tungsten as the hard phase and nickel, iron, copper and other metal elements as the binder phase.

2. Characteristics

Ø 1) High hardness (86～93HRA, equivalent to 69～81HRC). Under other conditions unchanged, the higher the content of tungsten carbide and the finer the grain, the greater the hardness of the alloy.

Ø 2) Good wear resistance. The material produced by the tool life than high-speed steel cutting 5 ~ 80 times higher; the material produced by the grinding tool life than steel grinding tool 20 ~ 150 times higher.

Ø (3) excellent heat resistance. In 500℃its hardness remains basically unchanged, in 1000℃when the hardness is still very high.

Ø 4）Strong corrosion resistance. Under normal circumstances, it does not reactwith sulfuric acid.

Ø 5) Good toughness. Its toughness is determined by the bonding metal, the higher the content of the bonding phase, the greater thebending strength.

Ø 6) Brittle. Its difficult to make a complex shape of the tool, because it can not be cut.

3. classification

According to the different binder, cemented carbide can be divided into the following categories:

Ø (1) tungsten-cobalt alloy: the main components are tungsten carbide and cobalt, which can be used to produce cutting tools, molds and geodesic products.

Ø (2) Tungsten-titanium-cobalt alloys: the main components are tungsten carbide, titanium carbide and cobalt.

Ø (3) tungsten-titanium-tantalum (niobium) alloy: the main components are tungsten carbide, titanium carbide, tantalum carbide (or niobium carbide) and cobalt.

According to the different shapes, the base can be divided into three kinds of spherical body, rod and plate. Non-standard products have unique shapes and need to be customized.

4. Preparation

Ø 1) Ingredients: raw materials are mixed in a certain proportion; 2) add alcohol or other media, wet grinding in a wet ball mill; 3) after crushing, drying, sieving and adding molding agents such as waxes or gums; 4)granulate the mixture, compression molding, and heating can be made to produce alloy products.

5. Usage

It can be used to make drill bits, cutting tools, rock drilling tools, mining tools, wear-resistant parts, nozzles, rotors andstators of electric motors and so on.