The influence of the Friction Stir Welding process on the non-heat-hardenable aluminum alloy AA5056 structure formation depending on the sheet workpiece rolling direction

Abstract

This paper is devoted to the study of friction stir welded joints made of 5-mm-thick aluminium alloy AA5056 sheet metal. These joints were produced using workpieces cut along and across the rolling direction of the material. Metallographic studies were carried out to determine the structural features of joints obtained by friction stir welding. Tensile tests across the weld were carried out to verify that the ultimate tensile strength requirements for the welded joint are met. It was found out that mechanical properties of joints are different depending on the rolling direction. In the case of welding along the rolling direction with varying parameters, a large number of welds have an ultimate tensile strength of at least 0.9 of the base metal one. In the case of welding across the rolling direction, in some cases the ultimate tensile strength of the weld exceeds that of the base metal. As a result of the research, it was found that when welding in different directions relative to the rolling direction, there is a wide range of friction stir welding parameters for 5-mm-thick workpieces made of AA5056 alloy, which also depends on the rolling direction of workpieces.