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What Factors Affect the Efficiency of Wire Cutting?

Jul. 22, 2021

The cutting efficiency is affected by two major factors, one is the current carrying capacity (current) of the wire, and the other is the erosion in the slit cannot be removed in time, and its conductive effect consumes the pulse energy. In short, total energy and energy utilization are both issues of cutting efficiency. As Wire Cutting Machine Manufacturers, I would like to share with you.

Split-type A CNC Wire Cut EDM-MS‍

Split-type A CNC Wire Cut EDM-MS

The industry has done many typical tests on the cutting efficiency of molybdenum material fast wire machine tools. The results prove that when the current carrying capacity of molybdenum wire reaches 150A/mm2, its tensile strength will be reduced to 1/3~1/4 of the original strength. , This current value is regarded as the limit of molybdenum wire carrying current for cutting. Calculated from this, φ0.12 carries 1.74A, φ0.15 carries 2.65A, and φ0.18 carries current 3.82A. Limit value of molybdenum wire. If the current carrying capacity is increased, there is no doubt that the life of the wire will be short. At a wire speed of 10 m/s, the DX-1 coolant of the Beijing Grease Chemical Factory cuts ordinary steel with a thickness of 50 and a pulse width of 32 mS. When the inter-pulse is 200mS, the cutting efficiency calculated by the volume of the erosion is 5.8mm3/min.A. Using this efficiency calculation, the area cutting efficiency of different thicknesses of molybdenum wire working at the maximum current carrying capacity is φ0.12~70.43mm2/min, φ0.15~90.41mm2/min, so calculated, the wire can be thickened by thickening it. With large current carrying capacity, the efficiency can be improved correspondingly when the current is large. However, the wire cutting with fast reciprocating wire is not allowed to increase the wire diameter to more than 0.23 (for reasons such as wire arrangement, deflection, loss, etc.), and due to the limitation of the discharge speed of the erosion material, when the current is increased to an average value of 8A At this time, there will be short-circuit or galvanic discharge in the gap, and short-term spark discharge without strong maintenance will also cause the loss of molybdenum wire to increase sharply, so blindly thickening the wire and increasing the current is not advisable. .

The ablation present in the gap is a resistive load. It short-circuits a part of the energy provided to the gap by the molybdenum wire. Therefore, when the cutting material is thickened and the removal of the ablation is more difficult, more energy is lost. , The effective machining pulse will be less, the discharge current becomes a linear load current, and the molybdenum wire is not formed for machining, which is the main reason for energy loss and wire breakage. In view of the two main factors that affect the processing efficiency, to increase the processing speed, corresponding efforts should be made in the following aspects:

1. Increase the energy of a single pulse, that is, the pulse amplitude and peak current. In order not to burden the wire's current carrying capacity, the pulse interval should be increased accordingly to prevent the average current from increasing too much.

2. Maintain the dielectric coefficient and dielectric strength of the coolant, maintain a high spark explosive power and cleaning ability, and minimize the short-circuit effect of the erosion on the pulse.

3. Improve the mechanical precision of the wire transporting and guiding system, because narrow seams always go faster than wide seams, and straight seams always go faster than folded seams.

4. Properly increase the wire speed to speed up the water brought into the gap by the wire, increase the amount of water, and discharge the erosion more effectively.

5. Increase the enveloping property of water to the silk outside the gap, that is, let the water start to speed under the drive of the silk, and the speeding water has a strong cleaning effect on the gap.

6. Improve the frequency conversion tracking sensitivity and increase the pulse utilization rate.

7. Reduce the commutation time of the wire motor, start faster, and increase the effective processing time.

Through the above-mentioned efforts, it is possible to increase the cutting efficiency to 100~120 mm2/min, and it is practical. As for raising the index higher, it is at the expense of reliability and continuous processing time.

Our company also has Split-type A CNC Wire Cut EDM-MS on sale, welcome to contact us.

wedm@hklitong.com