At present, aluminum sheet alloy is widely used in the product processing and manufacturing industry. Due to the influence of external force or welding stress during the processing and manufacturing process, aluminum sheet products usually produce a certain degree of deformation, and these deformations usually have to be corrected to make them meet the product quality requirements. Practice has shown that most of the deformed components can be corrected. The principle of correction is to try to cause a new deformation to offset the deformation that has occurred. In the actual process of production of commonly used correction methods, mainly mechanical correction, manual correction and flame correction, so to choose the best correction method for different structures and deformation of the product to obtain the best correction effect.
The cause of deformation of aluminum plate components
The deformation of raw materials in the processing process
Deformation caused by the residual stress in the extrusion process of raw materials. Such as: inconsistent cooling speed in the extrusion process, extrusion equipment commissioning malfunction, etc.
Deformation in the product manufacturing process
The main reason is the impact of external forces. Such as shear extrusion stress generated in the shearing process, thermal expansion and contraction stress generated in the thermal cutting process.
Deformation generated in the welding process
The main reason is the transverse and longitudinal shrinkage stress around the weld, usually referred to as the deformation caused by welding stress.
The essence of the component deformation
No matter what kind of deformation occurs in the component, the main reason is due to the existence of different degrees and different forms of residual stresses inside it, so that part of the fibers in its structural organization become longer by the surrounding compressive stress, and part of the fibers become shorter by the surrounding tensile stress, thus causing the deformation of the metal material.
The principle of deformation correction and common methods of aluminum plate components
The principle of correction is to make the longer fibers shorten and the shorter fibers elongate through external force or local heating, and finally make the fiber length of each layer converge or reach the fiber length we require, so as to eliminate the deformation or make the deformation reduced to within the specified range.
Various correction methods in the field to use the process according to the structural characteristics of its members, deformation form, workpiece size and other different situations to do the corresponding selection, if necessary, also need to take a variety of correction forms combined with the comprehensive correction method. Among them, flame correction is the most widely used a method for large components and their own strength of the larger components of the deformation correction effect is best, but flame correction is also a more difficult to master the correction method, such as heating position, temperature control, cooling mode is not appropriate will cause a new component of greater deformation, and even lead to product scrap. Therefore, the flame correction operators in addition to a wealth of practical experience, but also need to master the heat treatment properties of the aluminum plate.
Aluminum alloy component deformation correction method
Aluminum plate profile and more than 8mm thick plate common correction equipment is the press. Generally speaking, the thicker the plate, the easier it is to level, the thinner the plate correction is more difficult. In the use of mechanical correction need to be added to the force part of the pad, in order to avoid the surface of the material to produce pressure injury. Straightening with presses is usually for single direction of bending deformation of steel sections. Usually also equipped with special pads and pressure blocks to ensure the stability of the direction of force, while avoiding crushing the surface of the material to ensure the quality of correction.
For the deformation of small local deformation can be manually corrected. The effect of manual correction depends on the correct choice of hammering parts, hitting tools and hitting methods.
Aluminum products in the choice of manual correction need to be careful, the implementation of manual correction need to consider the use of appropriate hitting tools, such as wood hammer, rubber hammer, nylon hammer, etc..
Consider adding rubber pads, wood chips or wood blocks to the stressed parts and pads and pressure parts to ensure that the material surface is not damaged during the correction process.
Flame correction often uses the following three heating methods: linear heating method, point heating method, triangular heating method.
Aluminum plate member deformation correction methods and correction principles and steel correction have many common aspects, the key is to master the correction of aluminum metal properties and heat treatment properties, especially the difference in thermal processing temperature and control means, the difference between the response, as the principle of the use of reasonable correction means to implement correction, that is, to obtain good correction results.