中文版
ENGLISHThere are many reasons for the deformation of aluminum parts, which are related to materials, part shapes, and production conditions. Deformation caused by internal stress of the blank, deformation caused by cutting force, cutting heat, deformation caused by clamping force. So, how to reduce the deformation of aluminum parts? Let's take a look at the measures!
The material and geometric parameters of the tool have an important influence on the cutting force and the cutting heat. The correct selection of the tool is essential for reducing the deformation of the part.Under the condition of maintaining the strength of the cutting edge, the front angle can be appropriately selected. On the one hand, the sharp cutting edge can be ground, and the cutting deformation can be reduced, the chip removal can be smoothed, and the cutting force and the cutting temperature can be reduced. Never use a negative rake cutter.
The back angle size has a direct impact on the flank wear and the quality of the machined surface. Cutting thickness is an important condition for selecting the back angle. In rough milling, due to the large feed rate, the cutting load is heavy, the heat generation is large, and the heat dissipation condition of the tool is required. Therefore, the back angle should be selected to be smaller. When finishing milling, the edge is required to be sharp, the friction between the flank and the machined surface is reduced, and the elastic deformation is reduced. Therefore, the back angle should be selected to be larger.
In order to smooth the milling and reduce the milling force, the helix angle should be chosen to be as large as possible. Properly reducing the lead angle improves the heat dissipation conditions and reduces the average temperature of the processing zone.
Reduce the number of milling cutter teeth and increase the chip space. Due to the large plasticity of the aluminum material, the cutting deformation during processing is large, and a large space for chipping is required. Therefore, the bottom radius of the chip groove should be large, and the number of teeth of the milling cutter is small.The roughness value of the cutting edge of the cutter is less than Ra = 0.4 um. Before using a new knife, you should use a fine stone to grind a few times in front of and behind the teeth to eliminate residual burrs and slight zigzag when sharpening the teeth. In this way, not only the cutting heat can be reduced but also the cutting deformation is relatively small.
When processing a thin-walled sheet workpiece, a vacuum chuck is selected to obtain a uniformly distributed clamping force, and then processed with a small amount of cutting, which can well prevent deformation of the workpiece. A stuffing method can also be used. In order to increase the process rigidity of the thin-walled workpiece, the medium can be filled inside the workpiece to reduce the deformation of the workpiece during the processing and clamping of the aluminum part.
