There are few and no composite materials processed by machining center, but it is strict to process composite materials with machining center, and there are some precautions:
Now the amount of composite materials has been rising, so the use of machining centers to add composite materials has also been rising. In the past, we used to drill and cut the edge by hand, but now we use machinery to finish it. Using machining center to process composite materials is much faster than manual processing, and the precision is high. However, once there is a problem, there will be serious loss. Therefore, the process, tool selection and processing parameters are particularly important for processing composite materials.
Matters needing attention in selecting cutting tools for machining composite materials
1、 Generally, the size of composite auxiliary materials is relatively large, and its workpiece structure is complex, and its hardness and strength are very high. The cutting force used in the machining process is relatively large, and the heat produced by the processing is difficult to transfer out, which may severely scorch the resin or soften the resin, resulting in severe tool wear. Therefore, the tool used must have carbon fiber, and the cutting speed should be greater than 500 / min, and the feed speed must be small. In the process of edge cutting, carbide hobbing cutter, electroplated diamond grinding wheel, diamond inlaid milling cutter and copper based diamond grain saw blade should be selected.
2、 The cutting effect of the three new types of special milling cutters for machining monolithic cemented carbide composites is better. They all have some common characteristics: high rigidity, small helix angle, even 0 ° angle. The specially designed herringbone blade can effectively reduce the axial cutting force and delamination, and their machining efficiency and effect are very good.
3、 The interlaminar strength of carbon fiber composites is low, and it is easy to produce delamination under the action of cutting force. Therefore, the axial force should be reduced when drilling or trimming. High speed and small feed are required for drilling. The rotating speed is generally 3000 ~ 6000r / min, and the feed rate is 0.01 ~ 0.04mm/r. It is better to select three tips and two edges or two tips and two edges for the drill bit. The sharp tip can cut off the carbon fiber layer first. The two edges play a repair role on the hole wall. The diamond embedded drill head is sharp and wear-resistant. It is a difficult problem to drill the interlayer between composite and titanium alloy. Generally, the integral cemented carbide bit is used to drill according to the cutting parameters of drilling titanium alloy. From the titanium alloy side, the drilling is carried out until the drilling is through. Lubricant is added during drilling to alleviate the burn of composite materials. Boeing company specially developed PCD combined bit for interlayer drilling.
Special attention: the composite chip is powder, which is harmful to human health. High power vacuum cleaner should be used for dust collection, and water cooling can also effectively reduce dust pollution
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