1. Optimize processing parameters
During the processing of Brass Accessories, reasonable process parameters are the key to solving the deformation problem. The first is the cutting parameters. Cutting speed, feed rate and cutting depth have a significant impact on deformation. When turning Brass Accessories, a moderate cutting speed should be selected. Too high a cutting speed will generate too much heat, causing local thermal expansion of the brass, thereby causing deformation. For example, for ordinary brass accessories, the cutting speed is generally controlled at 100-200m/min.
The feed rate also needs to be adjusted carefully. Excessive feed rate will increase the cutting force and cause greater deformation of Brass Accessories. Usually, the feed amount is controlled at 0.1-0.3mm/r according to the size and accuracy requirements of the accessories. At the same time, a reasonable cutting depth can disperse the cutting force and avoid stress concentration. Generally, the cutting depth does not exceed 2-3mm each time. In addition, when milling Brass Accessories, the use of down milling can reduce cutting forces and reduce deformation, because the direction of the tool cutting in and out during down milling is conducive to reducing the impact on the workpiece.
2. Improve the clamping method
The clamping method has an important influence on the processing deformation of Brass Accessories. Traditional clamping methods may cause deformation of accessories due to uneven distribution of clamping force. Adopting appropriate fixtures and clamping strategies is an effective way to solve the problem. For example, using a soft-claw clamp, the soft-claw material is generally made of softer metals such as copper or aluminum. When clamping Brass Accessories, it can better fit the surface of the accessory and evenly distribute the clamping force.
For Brass Accessories with complex shapes, multi-point clamping or auxiliary support can be used. Multi-point clamping can disperse the clamping force and reduce deformation caused by excessive local pressure. Auxiliary supports can provide additional support for accessories during processing to prevent deformation due to cutting forces. At the same time, pay attention to controlling the clamping force when clamping. Use accurate pressure sensors or empirical formulas to determine the appropriate clamping force according to the size and shape of Brass Accessories to avoid over-clamping.
3. Reasonable processing sequence and margin allocation
The processing sequence and allowance allocation are crucial to the deformation control of Brass Accessories. When formulating the processing sequence, the principle of roughing first and then finishing should be followed. During rough machining, a certain machining allowance is left to remove most of the material. At this time, due to the large machining allowance, the cutting force generated is also large, but the accuracy requirements are not high. Through rough machining, the residual stress inside the brass raw material can be released.
In the finishing stage, the allowance should be gradually reduced, and generally the finishing allowance is controlled at 0.2-0.5mm. This can gradually reduce the cutting force during the machining process, thereby reducing the deformation effect on Brass Accessories. At the same time, for Brass Accessories with symmetrical structures, symmetrical processing is adopted, that is, processing from both sides to the middle or from the middle to both sides simultaneously can balance the stress generated during the processing and effectively prevent deformation.
4. Carry out stress relief treatment
Brass Accessories can effectively solve the deformation problem by performing stress relief treatment before and after processing. Stress relief annealing is a common method for brass raw materials before processing. The brass material is heated to a certain temperature (usually 260-300°C), kept warm for a period of time (about 1-2 hours), and then cooled slowly. This eliminates the residual stress created in the brass during the casting or rolling process, reducing the possibility of deformation due to stress release during machining.
After processing, if it is found that Brass Accessories still have a certain degree of deformation, straightening or shaping processes can be used. For small Brass Accessories, a press can be used for alignment, and the deformed parts can be restored to their original shape by applying the appropriate amount of pressure. For Brass Accessories with large or complex structures, it is necessary to use special shaping fixtures or processes, combined with auxiliary means such as heating, to accurately repair the deformed parts to meet the size and accuracy requirements of the product.
