Aluminum parts processing technology to solve the problem of aluminum parts processing deformation（4）

　 3. Improve the clamping method of the workpiece

　　 For thin-wall aluminum parts with poor rigidity, the following clamping methods can be used to reduce deformation:

　　 ① For thin-walled bushing parts, if a three-jaw self-centering chuck or spring chuck is used to clamp from the radial direction, the workpiece will inevitably deform once loosened after processing. At this time, the method of compacting the axial end face with better rigidity should be used. Position the inner hole of the part, make a threaded mandrel, and insert it into the inner hole of the part. Use a cover plate to press the end face and tighten it with the nut. When machining the outer circle, clamping deformation can be avoided, and satisfactory machining accuracy can be obtained.

　　②When processing thin-walled and thin-plate workpieces, it is best to use vacuum suction cups to obtain a uniformly distributed clamping force, and then use a smaller amount of cutting to process, which can prevent the workpiece from deforming.

　　 In addition, you can also use the padding method. In order to increase the process rigidity of thin-walled workpieces, media can be filled inside the workpieces to reduce the deformation of the workpieces during clamping and cutting. For example, pouring urea melt containing 3% to 6% potassium nitrate into the work piece, after processing, immersing the work piece in water or alcohol, the filler can be dissolved and poured out.

　　 4. Arrange the process reasonably

　　 During high-speed cutting, due to the large machining allowance and intermittent cutting, the milling process often generates vibrations that affect the machining accuracy and surface roughness. Therefore, the CNC high-speed cutting process can be generally divided into: roughing-semi-finishing-angle processing-finishing and other procedures. For parts with high precision requirements, it is sometimes necessary to perform secondary semi-finishing and then finishing. After roughing, the parts can be cooled naturally to eliminate the internal stress generated by roughing and reduce deformation. The remaining amount after roughing should be greater than the amount of deformation, generally 1~2mm. When finishing, the finishing surface of the parts should maintain a uniform machining allowance, generally 0.2 to 0.5mm, so that the tool is in a stable state during the machining process, which can greatly reduce cutting deformation, obtain good surface processing quality, and ensure Product accuracy.