What factors affect the stretching effect when using a drawing die for production?

Wire drawing dies are essential tools for the stretching of wire materials. The stretching process involves utilizing a certain amount of tensile force to deform the billet plastically through the die holes of the wire drawing die, resulting in a reduction in cross-sectional area and an increase in length—a method of pressure processing. Stretching falls within the scope of pressure processing, and during the stretching process, except for the generation of a minimal amount of powder and屑, there is little change in volume. Therefore, the volume of the metal before and after stretching is essentially equal. What factors can affect the stretching effect when using wire drawing dies for production?

1. Processing Materials: Under the same usage conditions, different types of wire materials require varying tensile forces. For instance, copper wire requires more tensile force than aluminum wire. With the same tensile force applied, aluminum wire is more prone to breaking. Therefore, different tensile force parameters must be set for wire materials of different compositions.

Material Strength: The chemical composition and rolling process, among other factors, can affect the strength of the material. The higher the tensile strength, the greater the required tensile force.

The degree of deformation. The greater the degree of deformation, the longer the length of the mold cavity deformation section, which in turn increases the positive pressure on the mold cavity alignment, along with an increase in friction and tensile force.

4. Friction Coefficient: The friction coefficient is determined by the surface smoothness of the wire material and mold material, as well as the composition and quantity of the lubricant. The higher the friction coefficient between the wire material and the die hole, the greater the tensile force.

5. The dimensions and shapes of the die hole working area and the sizing area. The larger the sizing area, the greater the tensile force.

6. Wire mold positioning. Improper placement of the wire mold or misalignment of the mold base can also increase the tensile force. It may even lead to non-compliance with wire diameter and surface quality standards.

7. External Factors. The wire being crooked, the wire's vibration during the pulling process, and the resistance from unwinding the wire all contribute to increased tensile force.