Most of the aluminum tubes on the market are produced by conventional combined die welding and extrusion process, which cannot completely avoid welding lines, especially dark lines after oxidation. In the extrusion production, the extrusion process of short round rod, high temperature and slow speed is used, especially the "three temperatures" should be controlled well. The aluminum rod, extrusion cylinder, and mold should be kept clean. The size of the pipe diameter can be adjusted appropriately.
The currently used aluminum tube extrusion machine includes an extrusion box and a cylinder. The heated aluminum block is put into the extrusion box from the feed port, and the cylinder starts to work so that the extrusion beam pushes the aluminum block toward the extrusion die. The high temperature The aluminum block in the state has good plasticity. When the temperature of the aluminum block decreases, the plasticity will also decrease. Under the certain pressure and speed of the extrusion beam, the extrusion pad pushes the aluminum block to produce plastic flow and extrude from the extrusion die. , so as to obtain the aluminum tube with the required cross-sectional shape and size; during the extrusion process, the aluminum block is in a strong state of pressure in the extrusion deformation zone, which can give full play to its plasticity and obtain a large amount of deformation, and the extrusion deformation can be improved. The structure of metal materials can improve its mechanical properties, especially for aluminum blocks with extrusion effect, the longitudinal (extrusion direction) mechanical properties of extruded products after quenching and aging are much higher than those of similar products produced by other processing methods. Press processing also has great flexibility. It is only necessary to replace the extrusion die to produce products with different shapes, sizes, specifications and varieties on the same equipment, and the operation of replacing the extrusion die is simple and convenient, time-consuming and efficient. But there are still big problems in the forming of some double-layer seamless aluminum tubes. Therefore, it is necessary to improve this situation.
The seamless aluminum pipe generally adopts the perforation extrusion method. Because the seamless aluminum pipe has the characteristics of small specific gravity, easy processing and high mechanical strength, in fact, the production process requirements of the seamless aluminum pipe are relatively strict and fine.
However, some problems should be paid attention to during production in order to produce seamless aluminum tubes with high quality. The following will share with you the problems that need to be paid attention to in the production process of seamless aluminum tubes and some successful practical experiences.
Large seamless aluminum tubes are generally hot extruded and then subjected to subsequent effective treatment. The small seamless aluminum tube can be hot extruded or cold drawn, and then subjected to subsequent effective treatment.
The alumina hydrate produced in the production process of the seamless aluminum tube requires continuous extrusion, and during the extrusion process, it is violently dehydrated to form blisters. In order to prevent blisters on the seamless aluminum tube, the round aluminum rod for extrusion should not have rolling cracks; it should not be stored in a humid environment, and the sodium hydroxide content in the cleaning solution should be about 30%. Control the aluminum ion content in the cleaning solution.