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The processing deformation of aluminum alloy shells, especially thin-walled shells, is a common technical problem. Therefore, our machining factory must analyze the cause of deformation, and then take corresponding countermeasures to prevent it.

1. The material grade and structural complexity of the aluminum shell will affect the deformation of the shell

The amount of deformation is related to the complexity of the shape, aspect ratio and wall thickness, which is directly related to the rigidity and stability of the material. Therefore, when designing the aluminum shell of the product, the influence of these factors on the deformation of the workpiece should be minimized.

Especially in the processing and customization of large-sized parts and shells, the structure must be reasonable. The hardness and porosity of the aluminum alloy material blank should be strictly controlled before processing to ensure the quality of the blank and reduce the deformation of the workpiece caused by it.

2. The deformation of the aluminum shell caused by the machining and clamping of the machining center

When processing aluminum shells and clamping material blanks, the correct clamping surface should be selected first, and then the appropriate clamping force should be selected according to the position of the clamping surface. Therefore, the clamping surface and the force-bearing surface should be kept as consistent as possible so that the clamping force acts on the workpiece.

When clamping forces from multiple directions act on the workpiece, the sequence of clamping forces should be considered. The clamping force should be applied first, so that the workpiece is in contact with the bracket, and it is not easy to be too large. The clamping force mainly used to balance the cutting force should be used in the subsequent process.

3. Deformation caused by aluminum shell processing parameters

During the cutting process of the machining center machine tool, the shell is subjected to the cutting force, which produces elastic deformation corresponding to the direction of the force, which is what we often call the machining industry. Corresponding measures should be taken in processing parameters and tool selection to deal with this deformation.

Sharp cutting tools are required for finishing machining. On the one hand, it can reduce the resistance formed by the friction between the tool and the workpiece, and on the other hand, it can improve the heat dissipation effect when the tool cuts the workpiece. Thereby reducing the residual internal stress on the workpiece.

When milling large surfaces of thin-walled casing parts, the single-edge milling method is usually used. The tool parameters adopt a larger entering angle and a larger rake angle to reduce cutting resistance. Because this kind of tool cuts lightly, runs fast, and reduces the deformation of thin-walled parts, it is widely used in production.

In the custom processing of thin-walled aluminum shells, a reasonable tool angle is crucial to the magnitude of the cutting force during processing, the thermal deformation generated during processing, and the microscopic quality of the workpiece surface. The size of the rake angle of the tool determines the cutting deformation of the tool and the sharpness of the rake angle.

A large rake angle reduces cutting deformation and friction, but if the rake angle is too large, the wedge angle of the tool decreases, the tool strength is weakened, the heat dissipation of the tool is poor, and the wear is accelerated. Therefore, when machining aluminum alloy thin-walled cavities, high-speed cutting tools and cemented carbide cutting tools are generally used. Correct selection of tools is the key to deal with the deformation of aluminum shell workpieces.

During processing, the heat generated by the friction between the CNC machine tool and the workpiece will also deform the workpiece, so high-speed cutting is often used. In high-speed machining, due to the short chip removal time, most of the cutting heat is taken away by the chips, which reduces the thermal deformation of the workpiece; secondly, when working in a high-speed machining center, due to the reduction of the softened part of the cutting layer material, it can also reduce the aluminum Deformation of shell machining helps to ensure that shells are of exact size, shape and size.

In addition, the cutting fluid of the CNC machine tool machining center is mainly used to reduce friction and reduce the cutting temperature during the cutting process. Reasonable selection of cutting fluid plays an indispensable role in improving the durability, surface quality and machining accuracy of the tool. Therefore, in order to prevent parts from deforming during machining, special cutting fluid with appropriate concentration must be used reasonably.

The use of reasonable cutting amount technology in CNC machining is an important link to ensure the accuracy of parts. When processing thin-walled aluminum shells with high precision requirements, symmetrical processing is generally used to balance the stress generated on the opposite surface to achieve a relatively stable state, and the processed workpiece will be as flat as possible.

However, when a large amount of cutting is used in a certain process, the workpiece will be deformed due to the imbalance of tensile stress and compressive stress. The deformation of the thin-walled aluminum shell during cutting by the machining center is various. Some factors such as the clamping force when clamping the workpiece, the cutting force when cutting the workpiece,

4. The deformation of the aluminum shell in the natural state after the machine tool of the machining center is dismounted

After the aluminum shell is processed, there will be internal stress and deformation in the processed part itself. In order to solve this situation, some workpieces need to be divided into rough machining and finish machining, that is, after rough machining is completed, aging treatment or heat treatment is carried out to remove stress, and then finish machining is carried out.