Compare cemented carbide dies with other parts

Cemented carbide dies dimensional accuracy, form and position accuracy is accomplished by grinding. As a result of the cemented carbide grinding force is on general steel grinding force of 2-3 times. So for grinding machine power is larger and higher rigidity, is China's current level of machine tool, has not been a special grinding machine for processing cemented carbide. Reason often cause processing error, error of the cumulative effect will seriously damage to the dies life. In edm process, because the moment the die materials of discharge is as high as 10000 ℃ high temperature effect and the effect of liquid medium, can make the change of the microstructure in the surface layers, and possibly carburizing (carbon) in working liquid, metals (copper, tungsten electrode), appear even micro crack, undoubtedly influence life span. Set is in order to make the alloy can withstand greater impact and extrusion load, both compression set set and cold press set set, clearance is very strict. General cold press set set of choice of 0.03 0.05 mm interference, hot-pressing set set of 0.08 0.1 Omm, cavity of heating take 700-700 ℃, carbide take around 300 ℃. In 600, after the completion of hot pressing chamber furnace heat preservation in 2 h, to eliminate stress.

cemented carbide welding is a key technology in general use brazing.In the process of welding,cemented carbide diess with important role. To introduce the following carbide dies and other components.

1) the cemented carbide die gap is bigger than ordinary dies, generally take 1.5 times that of ordinary steel.

2) when using elastic unloading division plate, stripper plate should be equipped with a guide, to the punch. In order to prevent the elastic impact when they hit the stripper plate in the blanking die of carbide blocks, mold closing, unloading division between plate and cemented carbide die due tmax 0.05 mm clearance, see figure 2.10.4.

3) to prevent cemented carbide die due to the bending deformation and fracture during cutting, in the bottom of the concave die should add hardening of thick plate.

4) for small punch its roots should be bold, or with a jacket in order to increase the rigidity of small punch and discharge guidance.