What are the factors that are prone to deformation in mechanical processing?

1. Workpiece deformation caused by workpiece clamping

Clamping the workpiece can easily cause deformation. To avoid this deformation, it is necessary to choose a suitable clamping point and then select the appropriate clamping force based on the position of the clamping point. Therefore, it is advisable to maintain the clamping point and support point of the workpiece as much as possible, so that the clamping force acts on the support and the clamping point is closer to the machining surface, which is less likely to cause deformation.

When clamping force is applied to the workpiece, the order of clamping force should be considered and the clamping force should not be too large. In order to balance the cutting force, the clamping force should be applied at the end. It is also necessary to increase the contact area between the workpiece and the fixture or use axial clamping force. The most effective way to solve clamping deformation is to increase the stiffness of the parts. The increase in the contact area between the workpiece and the fixture helps to reduce the deformation of the workpiece during the clamping process.

2. Workpiece deformation caused by the material and structure of the workpiece

The size of deformation is directly proportional to the complexity of the shape, aspect ratio, and wall thickness, as well as the stiffness and stability of the material. Therefore, when designing parts, minimize the impact of these factors on workpiece deformation as much as possible. Especially the structure of large components should be more reasonable. Before processing, defects such as hardness and looseness should be strictly controlled to ensure the quality of the blank and reduce workpiece deformation.

3. Workpiece deformation caused during mechanical processing

During the cutting process, the workpiece is subjected to cutting force, resulting in the phenomenon of tool yielding. This is the elastic deformation in the direction of force. To solve this deformation problem, the cutting tool can be improved, which can reduce the friction between the tool and the workpiece, improve the cooling capacity of the workpiece during the cutting process, and reduce the internal stress of the workpiece.

4. Workpiece deformation caused by stress after mechanical processing

After mechanical processing, the parts themselves have a relatively balanced internal stress state. Although the shape of the parts is relatively stable at this time, when some materials are removed and heat treatment is carried out, the internal stress will change, so it is necessary to restore the balance of forces. In this case, improvement should be made by folding the workpiece that needs to be straightened to a certain height, pressing the fixture into a flat state, and then placing the fixture and workpiece together in a heating furnace. Different heating temperatures and times should be selected according to the material of the parts. After hot straightening, the internal structure of the workpiece can remain stable. At this point, the workpiece not only has high straightness, but also eliminates work hardening, making it easier for further precision machining of the part.

5. Summary

For workpieces that are prone to deformation in mechanical processing, corresponding improvements should be made in both the blank and processing technology. The above points are the main factors that can easily cause workpiece deformation in mechanical processing. Major mechanical processing plants should pay attention to letting operators understand these main factors that cause workpiece deformation when training mechanical processing operators.