Do you really know what are the main characteristics of cemented carbide materials?

Cemented carbide is an alloy material made of hard compounds of refractory metals and bonding metals through powder metallurgy. It is basically different from the ingredients and preparation methods contained in it, so it has various functions. What are the main characteristics of cemented carbide materials? Let me sort out the main characteristics of cemented carbide materials for you:

1) There is no directionality in cemented carbide. Cemented carbide is made of powder by pressure sintering. Because the casting process is not used, there is no difference in density between the surface layer and the internal components, thereby eliminating the local mechanical function differences that may be caused by density differences.

2) There is no heat treatment problem with cemented carbide. In addition to the influence of thermal stress during heating and cooling, its mechanical function does not change due to heating and cooling (for example, even after heating to 1000°C and cooling, the mechanical function does not change). Therefore, for the processing of this type of cemented carbide, pre-processing cannot be performed under softened strips, that is, the pre-processing of cemented carbide must be carried out before sintering, and after sintering, except for processing with diamond tools or electrical machining methods In addition, it cannot be processed by other simple methods. The mechanical properties of cemented carbide are mainly determined by the cobalt content and the particle size of tungsten carbide.

3) Young's modulus of elasticity of cemented carbide is large, Poisson's ratio is small, and Poisson's ratio of cemented carbide is 0.21~0.24. Therefore, under the action of processing stress, the size change of the inner diameter of the cemented carbide mold is much smaller than that of the steel mold, so the product that is very close to the mold size can be obtained.

4) Cemented carbide has high compressive strength. The compressive strength is related to the cobalt content, and the low-cobalt cemented carbide can reach more than 6000Mpa, which is close to twice that of east-west steel. Therefore, it is advantageous for this material to be used in the working part of the cold extrusion die with high unit pressure.

5) The thermal expansion coefficient of cemented carbide is small. Compared with the east-west steel thermal expansion coefficient of 11×10-6/K, the cemented carbide is 5~7×10-6/K, which is smaller. This should be considered when designing and manufacturing the mold.

6) High thermal conductivity. The thermal conductivity of cemented carbide is three times higher than that of east and west steel. It can avoid the sintering problem between the processed material and the mold.

7) The amount of elastic deformation and plastic deformation is very small. This is an advantage for the mold, but it shows an unfavorable aspect. It is that the corresponding concentration in the mold is very sensitive, and it is easy to cause damage to the mold. This is a major issue in the design and application of cemented carbide molds.