CNC Knowledge: Reduce process measures and operational skills of aluminum treatment deformation!

There are many reasons for processing and deformation of aluminum parts, which is linked to materials, parts of part, production conditions, etc. There are mainly the following aspects: deformation caused by the stress caused by the rough internal stress, the deformation caused by the cutting force and the cutting heat, and the deformation caused by the tightening force.

1. Artisanal measures to reduce the deformation of treatment

1. Reduce the internal stress of white

The use of natural or artificial speed and vibrations can be partially eliminated to eliminate the internal constraint of white. The pre-processor is also an effective process method. For fat heads of large ears, due to the large amount of balance, deformation is also important after treatment. If the excess of white is prepared in advance to reduce the quantity of each part, it can not only reduce the treatment of treatment of the subsequent process, but also put it for a period after pre-procedure, and a certain stress internal can be released.

2. Improve the cutting capacity of the tool

The materials and geometric parameters of the tool have a significant impact on the cutting force and the cutting heat.

1) Reasonable selection of geometric parameters with a knife.

① The front of the front: under the condition of maintaining the resistance of the blade, the front angle is selected in an appropriate manner. Then reduce the cutting force and the cutting temperature. Do not use a negative tool of the front angle.

② The rear angle: the size of the rear angle has a direct impact on the wear of the rear knife surface and the quality of the treatment surface. Cutting thickness is an important condition for selecting the rear angle. During rough grinding, due to the large supply volume, the heavy cutting load and the large thermal mass, the knife must have good heat dissipation conditions. During fine grinding, the blade is sharp, reduce the friction of the surface of the rear knife and the surface of the treatment and reduces the deformation of flexibility.

③ Spiral angle: In order to stabilize and reduce the strength of grinding, the spiral angle must be as large as possible.

④ Senior partial angle: correct reduction in the main partial angle can improve heat dissipation conditions and reduce the average temperature of the treatment area.

2) Improve the structure of the tool.

① Reduce the number of milling teeth and increase the space of the full. Due to the great plasticity of aluminum materials, cutting the cut during treatment is large and a large amount of containment space is required. less.

② Essence of knife teeth. The roughness value of the blade blade is less than RA = 0.4um. Before using a new knife, use fine oil stones to gently grind the front and back of the blade to eliminate the burrs and slight sawtooth patterns remained when the blade crushing the teeth of the knife knife . In this way, not only can cut heat reduce, but also the cutting deformation is relatively low.

③ Strictly control the wear standards of the tool. Once the tool has been worn, the surface roughness value of the part increases, the cutting temperature increases and the room deformation increases. Therefore, in addition to the use of a tool material resistant to a well, the tool standard of the tool should not be greater than 0.2 mm, otherwise it will be subject to dandruff tumors. When cutting, the room temperature generally does not exceed 100 ° C to avoid deformation.

3. Improve the parts installation method

For aluminum parts with thin walls with poor rigidity, the following tightening methods can be used to reduce deformation:

① For thin lining parts, if you use three claws to customize the card or spring chip, tighten the radial steering. Currently, the axial facial pressing method with better rigidity should be used. The positioning in the inner hole of the parts, self-axle a threaded axis, put it in the interior holes of the room and use a blanket to compact the final surface and use the wire to tighten the back. When the treatment is rounded, it can avoid tightening and deformation, in order to obtain satisfactory treatment accuracy.

② When processing the part with thin plates, it is preferable to choose an empty suction to obtain a tightening force uniformly distributed, then from treating it with a smaller quantity of cut, which can prevent the deformation part.

In addition, you can also use the filling method. In order to increase the rigidity of the thin parts, it can fill the inside of the room to reduce the deformation of the part during the loading and cutting process. For example, the fusion of urea containing 3% to 6% of potassium nitrate is irrigated in the room.

4. Reasonable arrangement

During the high speed cut, due to the large amount of treatment and processing of treatment, the milling process often produces vibrations, which affects the treatment accuracy and surface roughness. Therefore, the CNC high -speed cutting process processing process can generally be divided into: processing processing processing processing treatment treatment treatment of rough treatment and other processes. For parts with great precision, a semi -seconded precision treatment is sometimes required, then a precision treatment is carried out. After a rough treatment, the parts can be cooled naturally, eliminating the internal stress generated by a rough treatment and reducing deformation. The quantity left after a rough treatment should be greater than the deformation, generally 1 to 2 mm. During refinement, the surface of the part of the part must be held uniformly treated. Cup deformation.

Second, reduce operational deformation treatment skills

The parts of the aluminum materials are distorted during treatment.

1. For parts with a large amount of treatment, in order to make better heat dissipation conditions during the processing process, avoid heat concentration and during treatment, symmetrical treatment should be adopted. If there is a 90 mm thick plate, it must be treated at 60 mm. The final size can ensure that the plan is 0.3 mm.

2. If there are several types of cavity on the parts of the plate, during treatment, it is not advisable to use a sequential treatment method of a cavity and a cavity. Use multiple processing layers, each layer as much as possible to all type cavities, then treat the following level to make the parts uniformly affordable and reduce deformation.

3. Reduce the cutting force and the heat of the cut by modifying the quantity of cut. Among the three elements of the quantity of cut, the amount of knife volume has a large impact on the cutting force. If the quantity of treatment is too large, the cutting force of the knife is once too large, which will deform not only the parts, but will also affect the rigidity of the main axis of the machine tool and will reduce the sustainability of the ‘tool. If you reduce the amount of knife, this will considerably reduce the effectiveness of production. However, high -speed grinding in CNC treatment can overcome this problem. While reducing the quantity of knife, as long as it increases accordingly, the speed of the machine-tool can be reduced and the cutting force can be reduced and the processing efficiency can be ensured.

4. The working order must also be special. Approximate treatment emphasizes the improvement in treatment efficiency and the continuation of the rate of unit time resection. In other words, withdraw the excess of materials on the surface of the rough at the fastest speed and in the shortest, and essentially form the geometric outline required by the precision treatment. The precision treatment emphasizes high and high quality precision, and it is advisable to use a smooth molding. Since the cutting thickness of the blade to the teeth decreases from maximum to zero during smooth grinding, the degree of hardening is considerably reduced and the degree of deformation of the parts is reduced.

5. The thin-world room is inevitable even if it is treated by a clip. In order to reduce the room deformation to the minimum, before the precision treatment is about to reach the final size, to loosen the compression parts to restore the part to the original condition, then tighten slightly The room. You can get the ideal treatment effect. In short, the role of tightening force is the best on the support surface, and the tightening force should act in the direction of good rigidity in the room. best.

6. When a cavity part is transformed, try not to let the millingr to drill the parts directly as a drill as possible, which leads to insufficient place for the milling cuttings, the dandruff are not smooth , causing overheating, swelling and collapse of the parts, collapse, collapse and collapse. First use the same size or the same drilling bit to pierce the knife holes of the same size or the same size, then use the mullet cut to mold. Alternatively, you can use CAM software to produce a spiral knife program.

The main factor affecting the processing accuracy and the quality of surface of aluminum parts is that it is subject to deformation when processing this type of parts, which requires that the operator has some operational experience and skills.