The cutting efficiency of electric spark fast wire cutting is affected by two major factors: the current carrying capacity of the molybdenum wire, and the inability to remove the corrosive substances in the cutting seam in a timely manner, which consumes the pulse due to its conductive effect. In short, overall, utilization is a matter of cutting efficiency?
Many typical experiments have been conducted in the industry on the cutting efficiency of wire cutting machines in molybdenum materials. The results have shown that when the current carrying capacity of molybdenum wire reaches 150A/mm2, its tensile strength will be reduced to 1/3 to 1/4 of its original strength. If the current carrying capacity is increased, the service life of the wire will undoubtedly be short. By thickening the molybdenum wire, the current carrying capacity can be increased, and the efficiency can be correspondingly improved as the current increases. However, it is not allowed to increase the wire diameter to 0.23 or above in wire cutting with wire routing, deflection, loss, and other reasons, And due to the limitation of the discharge speed of the eroded material.
The erosion material in the gap presents the effect of resistance load, which shortcircuits a part of the material provided by the molybdenum wire to the gap. Therefore, when the cutting material thickens and it is more difficult to discharge the erosion material, the loss is more and the effective processing pulse is less. The discharge current becomes a linear load current, which cannot be processed and only heats the molybdenum wire. This is the main reason for loss and wire breakage.
In response to the two main reasons that affect processing efficiency, efforts should be made to improve processing speed in the following areas:
1. To increase the amplitude and peak current of a single pulse, and not to burden the current carrying capacity of the molybdenum wire too much, the pulse interval should be correspondingly increased to prevent the average current from increasing too much.
2. Maintain the dielectric coefficient and insulation strength of the BM series working fluid, maintain high spark explosion force and cleaning ability, and minimize the short circuit effect of the etchant on the pulse.
3. Improve the mechanical accuracy of the wire guide system, as narrow seams always travel faster than wide seams, and straight seams always travel faster than zigzag seams.
4. Appropriately increase the wire speed to increase the speed of water introduced into the gap, increase the amount of water, and more effectively discharge the eroded material.
5. Increase the enveloping effect of water on the molybdenum wire outside the gap, that is, let the water accelerate under the drive of the wire, and the accelerating water has a strong cleaning effect on the gap.
6. Improve frequency conversion tracking sensitivity and increase pulse utilization.
7. Reduce the commutation time of the wire feeding motor, start faster, and increase effective processing time.
