Aluminum profile is one of the most widely used non-ferrous metal structure materials. Aluminum profile with a low density but relatively high strength is close to or surpasses the high-quality steel and it also has good plasticity so that it can be processed in various. What’s more, with excellent conductivity, thermal conductivity and corrosion resistance, the applications of the aluminum profile are widely used in the aviation, aerospace, automotive, machinery manufacturing, ship and chemical industry.
Aluminum profile in the process of processing, especially in the machining process, is prone to greater stress to deformation causing the ultra-size scrapped, and some avoiding deformation at the time can deform still after installed, resulting greater system problems. For stress relief of aluminum profile, the current methods include thermal aging, vibration aging, mechanical stretching, the mold corrective cold-pressing, etc.
Thermal aging for stress relief is generally for small and medium machining aluminum parts, which is a traditional way to stress relief. Because a lot of aluminum profile material is very sensitive to temperature, the limited aging temperature can not be too high; otherwise it will reduce the strength of the material. Thus, the thermal aging is usually carried out at a temperature of not higher than 200 ° C, and the efficiency of the stress relief can only be removed by about 10-35% at the same time.
The vibration aging for stress relief is to use controlled vibration energy to act on the processed product by the exciter sandwiched on the product surface, and to carry out the vibration treatment at a certain frequency, so as to achieve the purpose of releasing and reducing the residual stress of the workpiece. This processing method is common in large structural parts, welding and casting parts, with removal effect of about 50-60%.
Mechanical stretching for machining stress relief is to exert a certain amount of permanent tensile along the rolling direction of the aluminum profile after the quenching plastic to deform. The tensile stress and the original quenching residual stress have plastic deformation after superimposing and the residual stress can be eased and released. The results show that the mechanical stretching method can relieve more than 90% of the residual stress. However, this method is only suitable for simple shape parts, and has high requirements on the uniformity of aluminum profile sheet before stretching, mostly used in aluminum processing plants.
The mold corrective cold-pressing method is to remove the residual stress in the complex shape aluminum profile forging die in a special finishing mold by means of a strictly controlled cold-shaped plastic, which is to adjust rather than to relieve the overall stress of the part. Through this method, the residual stress on some parts of the aluminum profile products is released, but it is possible to make the residual stress of other parts increase at the same time. In addition, in view of the workpiece has already a large residual stress, the excessive deformation may lead to cold hardening, cracking and fracture, the insufficient deformation may lead to poor effect of stress relief, and what’s more, the high cost of making plastic mold and difficult operation limit this method difficult to apply in practical.
LINKEDALU METAL GROUP CO.,LTD.
We provide customers with quality products and provide high-quality services.