Matters in the design of tungsten carbide drawing die (3)

       Stretch coefficient m
 
Stretch coefficient is one of the main process parameters in the calculation of the stretching process, usually used to determine the sequence and number of stretching.
 
There are many factors that affect the stretch coefficient m, including material properties, relative thickness of the material, stretching method (referring to whether there is a blank holder), stretching times, stretching speed, punch radius, lubrication, etc.
 
In the process of repairing the mold, the relative thickness of the material, the stretching method (referring to whether there is a blank holder), and the number of stretching are not easy to adjust. You must be careful. When selecting the stretch coefficient m, it is best to check with a colleague.
 
5. Selection of processing oil for tungsten carbide deep drawing die
 
The choice of processing oil is very important. The way to judge whether the lubricant is appropriate is when the product is taken out of the mold. If the product temperature is too high to be touched by hand, you must reconsider the choice of lubricant and the lubrication method, and apply lubricant on the cavity or on the thin plate. Put a film bag on top.
 
If there are tensile cracks, apply lubricant on the concave mold (the convex mold is not coated with lubricant), and cover the workpiece with a 0.013-0.018mm plastic film on the side of the concave mold.