At the beginning of five, the difficulty of using Aluminum Alloy domestic Aluminum Alloy body, just imitating the structure and process in foreign countries, but in the specific production process, engineering and technical personnel gradually realized Aluminum Alloy manufacturing is a complex technology, the simple pursuit of design technology and technology are not
To obtain good results, for example, in the structure of a forming groove depth size is too large, too small, transverse size is too wide, too narrow may cause fatal quality problems on the structure, and these problems, and not like the steel body that can solve. Therefore, the research Aluminum Alloy body comprehensive technology is the key of manufacturing Aluminum Alloy vehicle, the key technologies of body design technology, automatic welding technology, welding deformation control, welding deformation correction technology, bending forming technology of aluminum plate, bending forming technology of large section profiles, component assembly technology, quality assurance and testing technology. Aluminum application in high-speed railway will encounter many technical problems, processing is much more difficult than steel. For example, most parts of the body are stamped by stamping, and if the stamping steel plate is used to punch the aluminum plate, cracks and wrinkles occur; the stamping performance of the typical shallow impact aluminum alloy body plate is basically the same as that of the steel plate. However, due to the poor deep drawing performance of aluminum alloy, in order to prevent the fracture, the concentrated drawing should be minimized, and the deep drawing should be well lubricated and the special-shaped billet should be used to facilitate the smooth flow of the metal into the die. The stamping die of aluminum alloy can be almost universal with steel, but the tool shape can be slightly modified to provide different rebound characteristics if necessary. For some extraordinary aluminum alloys, local or step-by-step operations, such as bending, flanging, flanging and blank flanging, can be carried out. The most of the car body are welded and assembled, aluminum welding should be much more difficult than steel and steel; connection characteristics Aluminum Alloy there are two main differences: one is the thermal conductivity and electrical conductivity of Aluminum Alloy is 3 times that of steel; two aluminum spot weld strength of 1/2 steel welds. The welding current density of the welding aluminum alloy is about 3 times of that of the steel, so the welding equipment of the two welding machines is not the same. The continuous welding of aluminum alloy must be carried out in sequence, but because of the short welding cycle time, the total welding time is equivalent to that of steel. For the large strength and quality requirements of the connection between aluminum alloy parts, the application of aluminum alloy automobile plate quality requirements are relatively high, appearance requirements smooth surface. In order to make the parts not damaged by the bad environment during the service, the parts must be electrophoresis and sprayed, which requires that the aluminum alloy automobile panels have better coating adhesion. Prior to painting, the surface of the aluminum alloy front hatch is polished more carefully. The coating process basically does not need change. Aluminum Alloy hatches and carbon steel can whole body in white electrophoretic coating, but after a long time will be in the electrophoresis liquid accumulating amount of Al ions. It is only necessary to add a mixture of sodium fluoride and potassium fluoride regularly in the electrophoretic solution to form a precipitate rich in sodium chlorate and then remove the Al ion after removing the phosphating bath.