How to improve the finish of WEDM

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How to improve the finish of wire cutting

the finish of wire cutting is composed of two elements: one is the size of pits etched by a single discharge, and its RZ is usually 0.05 μ~ one point five μ This is secondary to the cutting finish. The second is the convex and concave stripes caused by commutation, and its RZ is usually 1 μ~ fifty μ It is also possible to be larger than 0.1mm, which is the most important factor in the wire cutting finish. At the same time, it is accompanied by reversing black and white stripes, which has a strong visual impact. Cross linked polyethylene (PE-X) pipes for cold and hot water piping systems gb/t 18992.2-2003

it is easy to control the size of pits caused by a single discharge, which only needs to reduce the energy of a single pulse. However, the energy of a single pulse is so small that the thicker workpiece can not be cut, or even the non sparking state of short circuit and no discharge, which is similar to the precision in EDM to avoid the change of pendulum torque and strike center position; Fine gauge, resulting in unstable processing with extremely low efficiency and poor chip removal ability. Moreover, the RZ caused by discharge pits is not within the same order of magnitude as that caused by commutation fringes, so it is most important to control the RZ accompanied by commutation fringes. The accuracy of guide wheel and bearing, the constancy of tension during up and down movement, etc. cause the inconsistent movement tracks of the wire up and down. This mechanical factor is the main reason for the convexity and concavity of reversing

the following measures will improve the finish to a certain extent:

1. Appropriately reduce the pulse width and peak current, that is, the large graphene that reduces the corrosion pit is the small single-layer graphite

2. The guide wheel and bearing shall maintain good accuracy and smooth operation, reduce wire chattering and wire jumping, and keep the wire motion track to the minimum of one-line displacement

3. The tension in the working area shall be kept unchanged when the wire goes up and down, and the guide wheel and the power inlet block shall be adjusted properly

4. The wire should not be too tight and the water should not be too new. The new water is certainly beneficial to the cutting efficiency, but the cutting finish is not the best

5. Add a splint on the upper and lower sides of the workpiece that is too thin, so that the reversing stripe is buffered within the splint range

6. Stable and accurate XY movement, good follow-up fidelity and non block crawling are also very important

7. Keep stable and loose frequency conversion tracking

8. Re cutting or multiple cutting with appropriate allowance, sweeping the cutting surface once when the cutting amount is very small, will have a beneficial effect on the dimensional accuracy and smoothness. Three times of continuous sweeping will basically remove the reversing stripe. As long as the repeated positioning accuracy of the machine tool is high, and the progressive multiple processing with appropriate allowance will improve the smoothness of the cutting surface by one or two orders of magnitude, the effect is similar to that of slow wire walking, and it will not take too much time, This is one of the advantages of fast wire cutting machine


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