c. The surface metamorphic layer is too thick. The instantaneous high temperature and high pressure generated during discharge and the rapid cooling of the working fluid cause the surface of the workpiece to produce a metamorphic layer different from the performance of the raw material workpiece after the discharge is completed. In general, the effect of the surface metamorphic layer on the processing results is unfavorable. In particular, if the surface deterioration layer is too thick, the wear resistance and fatigue resistance of the machined surface are greatly reduced, which adversely affects the service life of the workpiece. The case where the surface metamorphic layer is too thick generally occurs at a place where the processing portion is relatively small because the processing energy of these processing portions is large. If the machined part has a small convex shape, a large current cannot be used in the roughing process, and the thermal influence of the excessive discharge energy affects the surface quality of the workpiece.
(3) Processing position deviation. After the completion of the processing, it is found that the electrode is biased is a common problem of abnormal processing. The way to clamp the workpiece and the electrode is to be firm and does not loosen during processing. Ensure the accuracy of the electrode and workpiece correction. In the positioning, you should use accurate reference and accurate positioning. Make sure the positioning standard is free of burrs and debris. Careful control of positioning accuracy is required during operation. At the beginning of the process, it is necessary to carefully observe whether there is any deviation in the processing part, and check whether there is any difference in the position of the processing part in the process. Careful attention to these points can prevent the occurrence of abnormalities in the machining position deviation.
(4) Anomalies in processing. The abnormal phenomenon in EDM can make the whole process cannot be carried out normally. Generally, the abnormal problems that often occur in processing are:
a. Processing efficiency is very low. The efficiency of EDM directly affects the efficiency of mold processing and should be properly controlled. Electrical parameters are the main cause of processing speed. The magnitude of the machining current is the most obvious condition in the electrical parameters. Generally, in roughing, the maximum current should be selected on the principle of ensuring a proper margin for finishing, which not only improves the processing efficiency, but also facilitates the finishing. If the current is too small in roughing, it first affects the efficiency of roughing, and because the finishing allowance is more, it also reduces the efficiency of finishing. Increasing the pulse frequency, that is, increasing the pulse width, and reducing the pulse gap are also methods for improving the processing efficiency. Other auxiliary electrical parameters are also important, such as increasing the discharge time and reducing the number of lifts. However, it is necessary to stabilize the processing. Otherwise, the working fluid in the processing zone cannot be de-ionized in time, and the electrolytic corrosion products cannot be discharged in time, which in turn leads to a decrease in processing efficiency. For example, in the case of large-area finishing, the length of the discharge time should be set to be very short, and the knife should be lifted. Only in this way can the processing be smoothly carried out, and the processing efficiency is substantially improved in the case where the discharge is stable. The quality of the working fluid and the impact of the oil flushing method are also obvious. High-quality EDM fluid should be used. When flushing oil, use reasonable flushing method to ensure smooth chip removal. It is recommended to immerse oil in large electrode processing. The processing part should be pre-processed with a proper margin. Excessive machining allowance increases machining time and greatly reduces machining efficiency. The depth margin reserved for roughing should not be too much, especially in the case of large area, because the erosion resistance of the finishing rule is very low, when the margin is too much, it will increase the processing difficulty and affect the processing efficiency.
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The quick stacking door has many functions such as heat preservation and cold preservation, insect and wind prevention, dust insulation and sound insulation. Widely used in underground parking lots, industrial plants, food, textiles, electronics, printing and packaging, automotive assembly, precision machinery, logistics and warehousing and other places.
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