Machining aluminum alloy parts can reduce the influence of residual stress on machining deformation. After the rough machining is completed, it is recommended to use heat treatment to remove the stress generated by the rough machining of the parts, so as to reduce the influence of stress on the quality of finishing. Improve machining accuracy and surface quality. After the rough and fine machining are separated, the finishing machining is just a small machining allowance, and the machining stress and deformation are small, which can greatly improve the quality of the parts. What are the technical requirements for machining aluminum alloy parts?
Five major technical requirements for machining aluminum alloy parts:
1. Selection of machining benchmarks for aluminum alloy parts:
The machining benchmark should be as consistent as possible with the design benchmark, assembly benchmark, and measurement benchmark, and the stability, positioning accuracy and clamping reliability of the parts should be fully considered in the machining technology.
2 aluminum alloy rough machining:
Since the machining dimensional accuracy and surface roughness of some aluminum alloy parts are not easy to meet the high-precision requirements, some parts with complex shapes need to be rough-machined before machining, and combined with the characteristics of aluminum alloy materials for cutting. The heat generated in this way will cause cutting deformation, increase the error of part size to varying degrees, and even cause deformation of the workpiece. Therefore, for rough machining of general planes, milling is used. At the same time, add coolant to cool the workpiece to reduce the impact of cutting heat on machining accuracy.
3. Finishing of aluminum alloy:
During machining, high-speed cutting will generate a large amount of cutting heat. Although the fragments can take away most of the heat, they can still generate extremely high temperatures on the blades. Due to the low melting point of aluminum alloy, the blades are often in a semi-melted state, making the cutting point The strength is affected by high temperature, and it is easy to produce concave-convex defects in aluminum alloy parts during machining. Therefore, in the finishing process, the cutting fluid with good cooling performance, good lubricating performance and low viscosity is usually selected. When lubricating the tool, take away the cutting heat in time, reduce the temperature of the tool and the machining surface of the part, and reduce the temperature deformation of the part.
4. Reasonable selection of tools:
Compared with ferrous metals, the cutting force generated by aluminum alloy materials during the cutting process is relatively small, and a higher cutting speed can be used, but it is easy to form debris. Aluminum alloys have a high thermal conductivity. Due to the high heat of the chips and parts during the cutting process, the temperature in the cutting area is low, and the durability of the tool is high, but the temperature of the parts themselves rises quickly, which is easy to cause deformation. Therefore, choosing a suitable tool material, choosing a reasonable tool angle, and improving the surface roughness of the tool are very effective in reducing cutting force and cutting heat.
5. Use heat treatment and cold treatment to solve machining deformation:
The heat treatment methods to eliminate the machining stress of aluminum alloy materials include: artificial timeliness, recrystallization annealing, etc. The process route of parts with simple structure generally adopts: rough machining, manual timeliness, and finishing machining. For parts with complex structures, the following general methods are used: rough machining, manual machining (heat treatment), semi-finishing, manual machining (heat treatment), and finishing. While arranging manual timely (heat treatment) process after rough machining and semi-finishing, a stable heat treatment process can be arranged after part finishing to prevent small dimensional changes during part placement, installation and use.
Three major technological processes for machining aluminum alloy parts :
The process for machining aluminum alloy parts can separate the rough and finish machining. After the rough machining is completed, the parts are heat treated to fully release the cutting stress and residual stress of the parts, and then finish machining, the machining quality of the parts will be greatly improved. Improvement, the separation of rough and finish machining has the following advantages:
1. It can reduce the influence of residual stress on machining deformation. After the rough machining is completed, it is recommended to use heat treatment to remove the stress generated by the rough machining of the parts, which can reduce the influence of stress on the quality of finishing. /2. Improve machining accuracy and surface quality. After rough machining and finishing machining are separated, finishing machining is only a small allowance, and the machining stress and deformation generated are small, which can greatly improve the quality of parts.
3. Improve production efficiency. Since rough machining is only to remove excess material and leave enough margin for finishing machining, the size and tolerance should not be considered too much, and the performance of different types of machine tools can be effectively utilized to improve cutting efficiency.
After the aluminum alloy parts are cut, the metal structure in the machining table will change greatly, and the influence of cutting motion will lead to a large residual stress. In order to reduce the deformation of the parts, it is necessary to reduce the residual stress of the material Fully released.M