Improving the quality and efficiency of friction stir welding of aluminum alloy plates

Abstract

Friction stir welding (FSW) is best suited for welding large-sized aluminum alloy parts. Finding optimal welding conditions and methods for minimizing defects arising during welding is an urgent task, the solution of which is necessary for the commissioning of FSW technology into the industry. The introduction of this method for welding rocket fuel tanks will increase the productivity of manufacturing products and their strength. The aim of this study is to improve the quality of friction stir welding of 7,6 mm thick Al-Mg6% aluminum alloys, as well as to increase productivity. The aim is achieved by finding optimal welding conditions and modernizing the welding method for simultaneous stripping by milling. The optimal welding modes found as a result of the study allow ensuring the strength of the welded joint, reaching 98% of the strength of the base material. The modernized welding method allows milling (deburring) to be carried out simultaneously with welding, which can significantly reduce the manufacturing time of the product, for which deburring is a necessary operation. As a result of the study, the welding modes were also revealed, leading to the appearance of hidden defects, which can reduce the strength of the welded joint by 2 times. A conditional diagram showing the appearance of defects in various combinations of modes has been compiled.