Effect of Friction Stir Welding on the Strength of Butt Joints of Aluminum Alloy 1565ch.

In friction stir welding, the rotation of the tool at the joint between the metal plates causes frictional heating and metal plasticising. Processes of intense plastic deformation effect the formation of the weld microstructure, determining strength properties. However, the main factor is the specific temperature and time conditions under which the friction stir welding process is implemented. It has been established experimentally that when temperature-time parameters are violated, defects in the form of weld discontinuities are localized at the weld-base metal boundary, the formation of which is caused by the incompatibility of the weld metal deformation and the adjacent base material. It is shown that the mechanism of destruction of a welded joint is determined by the presence of defects reducing the effective cross-section of the welded joint. [ABSTRACT FROM AUTHOR]