A newly developed plug in the drawing process for achieving the high accuracy of aluminum rectangular tube

Abstract

Aluminum rectangular tube is the key component in the field of microwave transmission whose service condition requests strict dimensional accuracy and internal surface quality. To meet these requirements, a newly developed plug featuring a tiny boss club structure in the sizing zone has been proposed in the plug drawing process. The optimal combination of the dimensions in the boss club has been obtained using the method of 3D finite element simulation and orthogonal experimental design. The plastic strain distribution, the contact status between the tube inner surface and the plug, the dimensional accuracy of the formed part, and the forming load have been compared between conditions where the traditional linear-type plug and this new type of plug have been used, respectively. It can be seen clearly that when the plug with a tiny boss club structure is adopted, the contact quality is better and the larger plastic strain exists on the inner surface of the tube, which is very crucial in improving the surface finish of the formed part. Meanwhile, the deviation of wall thickness and the axial length in the formed part is smaller based on the new type of plug. The experiment of the drawing process with two types of plugs has been carried out in which the surface finish of the inner tube surface and the wall thickness have been measured and compared. Experiment result shows that the dimensional accuracy and inner surface quality meet the requirements of the service condition when the plug with a tiny boss club structure is employed.