Aluminum alloy is an important industrial raw material, so Aluminum Parts CNC Machining is the most common in CNC machining. Due to its relatively small hardness and large thermal expansion coefficient, it is easy to deform in the machining of thin-walled and thin-plate parts. In addition to improving the tool performance and eliminating the internal stress of the material by using aging treatment in advance, from the perspective of the processing technology, some measures can also be taken to minimize the processing distortion of the material. For aluminum alloy parts with large machining allowances, in order to create better heat dissipation conditions and reduce thermal deformation, it is necessary to avoid excessive concentration of heat as much as possible. The method that can be adopted is symmetrical processing.

First, the layered multiple processing method

When multiple cavities need to be processed on aluminum alloy plate parts, if one cavity and one cavity are sequentially processed, it is easy to cause the cavity wall to be entangled and deformed due to uneven force. The best solution is to adopt the multi-layer processing method, that is, all the cavities are processed at the same time, but not in one process, but in several layers, and processed to the required size one by one. In this way, the force of the part will be more uniform, and the chance of deformation is smaller.

Second, the appropriate choice of cutting amount

Choosing the right amount of cutting can effectively reduce the cutting force and heat during the cutting process. During the machining process, the excessive cutting amount leads to excessive cutting force in one pass, which easily causes deformation of the part, and affects the rigidity of the machine tool spindle and the durability of the tool.

CNC Machined Aluminum Parts

Third, improve the cutting ability of the tool

The material and geometric parameters of the tool have an important influence on the cutting force and cutting heat. Correct selection of the tool is very important to reduce the deformation of the CNC Machined Aluminum Parts.

1. Reasonable selection of tool geometry parameters

(1) Front angle

Under the condition of maintaining the strength of the cutting edge, the rake angle is appropriately selected to be larger, on the one hand, it can sharpen the sharp cutting edge, and on the other hand, it can reduce the cutting deformation and smooth the chip removal, thereby reducing the cutting force and cutting temperature. Never use a negative rake tool.

(2) Rear angle

The rake angle has a direct impact on the flank wear and the quality of the machined surface. Cutting thickness is an important condition for selecting the relief angle. During rough milling, due to the large feed amount, heavy cutting load and large heat generation, good heat dissipation conditions of the tool are required, so the back angle should be selected smaller. During fine milling, sharp edges are required to reduce the friction between the flank and the machined surface and reduce elastic deformation. Therefore, the rake angle should be larger.

(3) Helix angle

In order to make the milling smooth and reduce the milling force, the helix angle should be selected as large as possible.

(4) Main declination

Properly reducing the main deflection angle can improve the heat dissipation conditions and reduce the average temperature in the processing area.

2. Improve tool structure

Reduce the number of cutter teeth and increase chip space. Because the aluminum alloy material is more plastic, the cutting deformation is larger during processing, and a larger chip space is required. Therefore, the chip groove bottom radius should be larger and the number of milling cutter teeth is better.

Fine grinding knife teeth: Before using a new knife, you should use fine whetstone to grind it a few times in front of and behind the knife teeth to eliminate burrs and slight jagged marks remaining when sharpening the knife teeth. In this way, not only the cutting heat can be reduced, but also the cutting deformation is relatively small.

Strict control of tool wear standards: After tool wear, the workpiece surface roughness value increases, the cutting temperature increases, and the workpiece deformation increases.

Fourth, the order of the knife is particular

Roughing and finishing should use different cutting sequences. Rough machining requires the fastest cutting speed to remove excess material on the surface of the blank in the shortest time to form the geometric contour required for finishing.

The above are the 4 methods to avoid deformation of parts in aluminum alloy processing introduced by Aluminum CNC Turning Cutting Factory.