Reasons for deformation of aluminum alloy parts of second-hand CNC machining center

The second-hand CNC machining center is easy to deform the parts when processing parts with lighter quality, poor rigidity, and weak strength, which directly affects the surface quality and processing accuracy of the parts. If the control is not good, the parts will be scrapped, resulting in greatly increased costs. , Do you know the causes of deformation of aluminum alloy parts in second-hand CNC machining centers and specific solutions? Today, Jiuku second-hand equipment will give you a detailed introduction.

There are three ways to deform parts, mainly including: deformation by force, deformation by heat and deformation by vibration.

Forced deformation: Such parts have thin walls. Under the action of clamping force, different thicknesses are likely to occur during machining and cutting, and the elasticity is poor, and the shape of the parts is difficult to recover by themselves.

Thermal deformation: The workpiece is light and thin. Due to the radial force during the cutting process, it will cause thermal deformation of the workpiece, which will make the size of the workpiece inaccurate.

Vibration deformation: Under the action of radial cutting force, parts are prone to vibration and deformation, which affect the dimensional accuracy, shape, position accuracy and surface roughness of the workpiece.

The main factors affecting deformation:

1. The state of the part material: different materials or different states of the same material have obvious differences in their deformation. For example, during cold working, the deformation of 2A12 aluminum alloy in the T4 state is much more serious than the deformation in the H112 state.

2. The structure of the parts: large and thin thin plate parts are prone to warping and distortion. Hollow frames, deep cavity thin-walled shells, and multi-islands are also prone to deformation.

3. Parts processing technology: parts clamping method, cutting route, cutting amount, tool material, tool geometric parameters, cutting fluid, CNC programming and other links will affect the deformation of the part.

Methods to solve the easy deformation of aluminum alloy parts:

1. Compensation measures layer by layer

For hollow frame parts with large cutting deformations, in addition to heat treatment during rough processing, rough machining, semi-finishing, and finishing must be arranged in the CNC milling process. In each processing stage, it can be subdivided into multiple processing , Use the radius and tool length to compensate for the uniform removal margin, so as to continuously reduce the amount of each cutting, to achieve the purpose of reducing the stress imbalance. Separating the rough and fine milling, the rough machining can improve the machining efficiency, and the finishing can ensure the machining accuracy .

In the hollow frame parts of the machining center, such parts will deform under the action of cutting force, clamping force, gravity and inertial force, which will destroy the positional relationship of the various components of the process system. The processing can be divided into multiple processing. , Increase the stress-relief heat treatment between each step, and leave a uniform margin of 1 mm and 0.5 mm in the amount of each cutting. Also, during processing, constantly change the clamping method and the clamping point position of the fixture, and pass the table pressure plate Or vise clamping makes the stress in equilibrium.

2, Multi-point decentralized clamping measures

Thin plate parts are parts with a relatively large area. You can use a part to be processed and then change a position to process other parts. The clamping method must be pressed against a larger working surface. For multi-point clamping of the workpiece, a combined fixture is generally used , It is necessary to maintain the stability of the clamping, but also to consider not affecting the cutting, advance and retreat, tool change and intermediate measurement during processing.

3. Optimization of CNC process flow

For deep-cavity thin-walled multi-island box (box) body parts, in addition to considering the use of the previous two measures, the programming process of the machining center must weigh the cutting method and cutting parameters. First of all, ensure that the machining allowance is uniform. Reasonably determine the processing order and processing methods of the parts. There are two ways to process the cavity during programming: one is the ring cutting method, and the other is the line cutting method.

The plane contour processing generally adopts the circular cutting method, leaving a finishing allowance along the contour boundary. First, use a flat-bottom end mill to pass the circular cutting or row cutting method to mill away the excess material of the cavity, and then follow the bottom surface and contour of the cavity. Pass the tool, finish milling the bottom surface and boundary shape of the cavity. Secondly, the tool specifications should also be selected reasonably to minimize the cutting heat of the tool. If the cutting fluid is selected properly, the thermal deformation in the part processing can also be reduced.

The above content is a detailed introduction to the causes and solutions of the deformation of aluminum alloy parts of the second-hand CNC machining center. I hope it will be helpful to you. If you want to know more about second-hand equipment, you may wish to pay attention to the second-hand equipment of Jiuku.