To solve the problem of drawing damage in the forming process of wire drawing dies and workpieces, the basic principle of reducing adhesive wear should be followed, and the starting point is to change the properties of contact pairs. The following are the three parts that constitute the contact pair, namely, the raw materials of the formed workpiece, the parts between the workpiece and the die, and the die.

1. Raw materials of formed workpiece

By surface treatment of raw materials, such as phosphating, plastic spraying or other surface treatment of raw materials, a layer of non-metallic mold layer is formed on the surface of the formed material, which can greatly reduce or eliminate the strain of the workpiece. This method is often costly, and requires additional production equipment and additional production processes. Although this method has some effects sometimes, it is rarely used in actual production.

2. Between workpiece and die

Adding a layer of PVC film between the mold and the forming material can sometimes solve the problem of workpiece strain. For the production line, the film can be continuously supplied through the mechanism, while for the stamping equipment with periodic production, one film is required for each piece of work, which affects the production efficiency. This method is also very expensive and can also produce a large number of waste materials. It is advisable to use this method for the production of small batches of large pieces.

In some cases where the forming load is very small, sometimes the problem of workpiece strain can be solved by adding lubricating oil or EP additive lubricating oil.

3. Mold

By changing the convex and concave ink materials of the die or surface treating the convex and concave dies of the die, the properties of such contact pairs as the formed material and the convex and concave dies are changed. Practice has proved that this is an economic and effective way to solve the problem of strain, and it is also a widely used method at present.

To sum up, there are many methods to solve the problem of surface strain of workpieces and dies. For specific cases, the method should be selected according to the size of workpieces and loads, production batches, types of materials to be processed, etc. Among all the methods to solve the problem of strain, the best one is to use cemented carbide as the die material and conduct chemical vapor deposition and TD coating on the surface of the male and female dies. Among them, TD coating has the highest cost performance.