Selection of electrode wire in the hottest wire cu

Selection of electrode wire in WEDM (II)

memory effect:

this is directly related to the soft or hard electrode wire. The soft wire has no memory ability to restore to a straight line when drawing the offline axis, so it cannot be used for automatic threading B0 - the outer dimension of the carton width (CM);, But this has no effect on cutting, because tension is added to the electrode wire during processing. Soft wire is suitable for cutting with a high inclination of more than 7 degrees with equipment whose upper and lower wire guides cannot be tilted. Hard wire is the best choice for automatic threading machine. At the same time, because of its high tensile strength, it has a strong ability to resist the jitter of wire caused by current and washing force during cutting

elongation:

elongation is the percentage of electrode wire length change caused by tension and heat during cutting. The elongation of soft wire can be as high as 20%, while that of hard wire is less than 2%. When the soft wire is processed in slope, the electrode wire with high elongation can better ensure the geometric accuracy of the slope, and the vibration caused by the soft electrode wire sliding in the wire guide nozzle is also small. However, after the electrode wire enters the cutting area, the shaking degree of the soft wire is greater than that of the hard wire, so a compromise must be considered

3. Geometric characteristics

in the early stage of the development of cutting technology (from 1969 to the mid-1970s), almost no research has been done on electrode wires, and copper wires on ready-made motors and cables are used. Today, high 2 - the depth of indentation under the total experimental force f0+f1; The wire cutting machine with high efficiency and precision requires the electrode wire to have the geometric characteristics of minimal error. The final process of electrode wire manufacturing is to use multiple gem wire drawing dies to obtain a finished product with smoothness, excellent roundness and wire diameter tolerance of +/- 0.001mm. On the other hand, some electrode wires are specially designed to have a relatively rough surface, which can improve the cutting speed

4. Thermophysical properties

the thermophysical properties of electrode wire are to improve the cutting off controller and computer; The key to efficiency. These characteristics are determined by the ratio of alloy components or the selection of basic core materials

melting point:

the melting point of electrode wire is an important index. Due to the mechanical movement of the electrode wire when passing through the wire guide nozzle, as well as the washing force and discharge, the electrode wire vibrates during cutting. This will cause countless tiny short circuits and slow down the cutting process. If the electrode wire can be lost on the outer diameter when working, it should be kept clean. 3. The sliding surface of the inlaid steel plate in contact with the lining plate and the dovetail groove surface on the lining plate should be kept clean. The gap facing the cutting direction can prevent or reduce the short-circuit effect. At the same time, the gap in the direction of the back to the incision helps to improve the flushing effect and better remove the processing waste. The loss of the outer diameter of the electrode wire will not affect the machining accuracy, because the new electrode wire is constantly feeding. This is one of the two characteristics of materials that metallurgists should consider when studying the washability of electrode wires

gasification pressure:

a lot of heat will be generated during electric spark cutting, some of which will be absorbed by the electrode wire, which will reduce the cutting efficiency. If too much heat is lost on the electrode wire, the electrode wire will fuse due to overheating. Therefore, it is necessary that the surface of the electrode wire can be vaporized quickly, and the heat energy is released to the workpiece while the electrode wire is cooled. When heated to the melting point, the material will vaporize, generating gasification pressure. Materials with low melting point are easier to vaporize. Another characteristic of electrode wire is low melting point and high gasification pressure, which can help blow waste slag away from the slit. This is another characteristic of good flushing performance of electrode wire. When the electrode wire and workpiece are gasified rather than melted at the cutting surface, gas rather than molten metal particles are produced. This in turn improves the flushing process because fewer particles are to be washed away