The cnc machining deformation of aluminum alloy precision parts is mainly caused by factors such as cutting force of the blank, deformation caused by cutting heat, deformation caused by internal stress, and deformation caused by clamping force. We cannot allow deformed products to complete final assembly. Therefore, in order to reduce processing deformation, aluminum alloy precision parts processing manufacturers can take various measures to improve the process and achieve the goal of reducing deformation. The first technique is to reduce the internal stress of the blank.
Firstly, reduce the internal stress of the blank.
Reduce the internal stress of the blank. By using natural or artificial aging and vibration treatment, the internal stress of the blank can be partially eliminated; Or improve the cutting ability of the tool. Reasonably select the geometric parameters of cutting tools and improve their 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 spindle 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 processing the outer circle, it can avoid clamping deformation and achieve satisfactory machining accuracy.
When processing aluminum alloy thin-walled and thin plate workpieces, it is best to choose vacuum suction cups to obtain uniformly 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 is often generated 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 be naturally cooled, eliminating the internal stress generated by rough machining and reducing deformation.
In addition to the above reasons, aluminum alloy parts may also undergo deformation during the machining process. In practical operation, the operating method is also very important. For parts with large machining allowance, in order to provide better heat dissipation conditions during machining and avoid heat concentration, symmetrical machining should be used during machining.
