Tungsten Carbide Drawing Die

Before discussing this content, it is necessary to make a simple estimation of the phenomenon occurring in the core during the drawing process. The factors related to the mold blank are mainly as follows: 

- the wire is produced when it comes into contact with the inner surface of the core. Surface friction and pressure on the mold wall;

- the pulling force that reduces the cross section of the wire;

-The thermal expansion caused by the temperature rise due to the plastic deformation of the wire. Therefore, the core must meet the predetermined values for the following physical and mechanical properties:

- high hardness value;

One - high vibration resistance;

- high wear resistance;

- Low coefficient of friction.

The material for preparing the core is usually a sintered tungsten carbide, natural diamond, or synthetic diamond. The use of molds made from natural ochre and synthetic diamonds has some limitations. In most cases, it is used to pull non-ferrous metals. For the drawing of carbon steel wires, it is usually used only when the wire is extremely thin. This article will focus on the application of sintered tungsten carbide. The natural diamond mold blank is composed of a single crystal, and the artificial diamond crystal blank is produced by sintering the calcite particles into a polycrystalline structure. The hardness of natural ettringite and synthetic diamond blanks is very high (about 400 Vickers hardness), but their vibration resistance is poor. Due to its fragility, it will cause a lot of inconvenience in the production process and use. Sintered carbide blank

Hard metals (or particularly hard sintered carbides) and wear resistant alloys are produced by powder metallurgy techniques. The sintering process includes a process of uniformly agglomerating the powder at a temperature below the melting point of the tungsten carbide. This is accomplished by first cold compression and then heating the mold blank under conditions that control atmospheric endurance or increase furnace vacuum or control hydrogen flow. The sintering process is carried out at a temperature of about 1200 to 1300"C. During the process, the blank is subjected to a volume shrinkage of about 40% and a line shrinkage of about 25, and the amount of shrinkage is related to the pressure applied in cold compression.

The components used to produce the mold blank gold material are:

- tungsten carbide powder having a particle size of 0.8 to 6 m;

- metallic cobalt powder with a particle size of 1 to 1.5 m;

- tungsten carbide and titanium carbide;

- Carbide and niobium carbide.

Tungsten carbide and titanium carbide increase hardness and wear resistance;

Carbide and carbonized saws increase vibration resistance, in other words, increase resistance to lateral cracking; metal drill powder is an element that homogenizes the alloy. The properties of sintered carbides, characterized by their microstructure, may be affected by the following factors:

- the chemical composition of carbides and alloying elements;

- the type and size of the powder;

- the ratio of carbides and alloying elements;

- excess or insufficient carbon.

Only a few brief explanations of these factors are given. The production process will be discussed in detail below. The tungsten carbide powder should be as uniform as possible in the range of 0.8 to 6, um. In actual production, the percentage of other various components is basically equivalent. If fine particles are used. The density can be increased to increase the hardness value of the sintered compact.