How to reduce deformation in CNC machining

How to reduce deformation in CNC machining

Firstly, reduce the internal stress of the blank.

Reduce the internal stress of the blank. The use of natural or artificial aging and vibration treatment can partially eliminate internal stress in the blank; Or improve the cutting ability of the tool. Reasonably select tool geometric parameters and improve tool structure. The second technique is to improve the clamping method of the workpiece.

Secondly, improve the clamping method of the workpiece.

For aluminum alloy thin-walled liner parts, if a three jaw self centering chuck or spring chuck is used for radial clamping, once the workpiece becomes loose after processing, it will inevitably deform. At this point, a method of axial end face compression with good rigidity should be used. According to the positioning of the inner hole of the part, make a self-made threaded mandrel and insert it into the inner hole of the part. Press the end face with a cover plate and support it with a nut. When CNC machining the outer circle, clamping deformation can be avoided, thereby achieving satisfactory machining accuracy.

When processing aluminum alloy thin-walled and thin plate workpieces, it is best to choose vacuum suction cups to obtain evenly distributed clamping force, and then use small cutting amounts for processing, which can effectively prevent workpiece deformation.

Third: Reasonably arrange the process

In high-speed cutting, due to large machining allowance and intermittent cutting, vibration often occurs during milling, which affects machining accuracy and surface roughness. Therefore, CNC high-speed cutting can generally be divided into rough machining, semi precision machining, cleaning machining, and precision machining. For parts with high precision requirements, sometimes secondary semi precision machining is required, followed by precision machining. After rough machining, the parts can naturally cool, eliminate internal stress generated by rough machining, and reduce deformation.

In addition to the above reasons, aluminum alloy parts can also undergo deformation during the CNC machining process. In practical operation, the operating method is also very important. For parts with large machining allowance, in order to have good heat dissipation conditions during processing and avoid heat concentration, symmetrical machining should be used during processing.