How to deal with large thickness cutting

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How to deal with large thickness cutting

it is difficult to cut large thickness in wire cutting processing, but it is not how high the wire frame can be raised that it can be cut. Restricted by the etching conditions of EDM, to a certain extent, the machining is very unstable until there is a short circuit with current and no discharge. Along with the pulling arc burn, the wire will be broken soon. In very unstable processing, the cutting surface will also form grooves, and the surface quality will be seriously damaged. The cutting seam is filled with very viscous corrosion substances, even powdery carbon black and corrosion particles

steel with large thickness but bearing 4000 vehicles usually refers to steel with a thickness of more than 200mm. As for other materials with higher conductivity, higher thermal conductivity or high temperature resistance, it is less than 200mm, such as red copper, hard alloy, pure tungsten, pure molybdenum, etc., it is very difficult to be 70mm thick

the main contradictions of large thickness cutting are:

· without enough water to enter and exchange, the corrosion cannot be removed from the gap, the insulation cannot be restored, and the discharge cannot be formed

· the filler in the gap diverts the energy of the pulse source in the form of resistance, resulting in the loss of sufficient breakdown voltage and single pulse energy between the wire and the workpiece

· due to the limitation of the current carrying capacity of molybdenum wire, it is impossible to transfer greater pulse energy to the gap catapult, which is comparable to the Fraunhofer Association in Germany

· the distance from the middle part of the cutting seam to discharge the corrosion is too long, and the attenuated spark discharge has not formed enough explosive force and sewage discharge force

· due to materials, the possibility of impurities and internal stress in large thickness is greatly enhanced. The probability of local abnormality and deformation of the slit is also large. The cutting impact force is lost, but the possibility of short circuit is increased

to solve the main contradiction of large thickness cutting, the following measures can be taken:

· increase the energy of a single pulse (the product of voltage, current and pulse width of a single pulse is the energy of a single pulse)., The purpose of increasing the pulse interval is to form the ability of spark discharge and enhance the explosive force of spark under the premise that the average current carrying capacity of molybdenum wire does not increase

· select the coolant with higher dielectric coefficient, stronger insulation recovery ability, stronger fluidity and blowdown solution

· greatly increase the pulse voltage, increase the discharge gap, and make it easier for water to enter and discharge. On January 28th, 2013, versalis of Italy and Yulex of the United States, which is engaged in agricultural biomaterials, announced that

· pre-treatment of cut materials should be done in advance, such as uniform organization by repeated forging, removal of impurities, and removal of internal stress of materials by annealing and effective treatment. The material stress can be fully released by removing large residual factors

· improve the wire speed, more stable wire transportation, and enhance the ability to carry water and resist short circuit

· the gap is effectively enlarged by the artificial offset broken line feeding or the automatic feeding mode of "two in and one out"


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