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The samples produced by friction stir welding of 35 mm thick rolled sheets of thermally non-heat-treatable aluminum-magnesium alloy AA5056 were investigated in this work. Macro- and microstructure was studied on metallographic specimens cut in a planar section relative to the welding zone through the thickness of the workpiece. It was found that in the zone of tool inlet the weld metal is extruded, then there is an adhesive interaction of the tool and welded material with its further layer-by-layer transfer, as a result of which the structure is represented by a mixture of material flows along the contour of the tool. [ABSTRACT FROM AUTHOR]

The work compares the strength characteristics and microstructure of 2-mm-thick welded joints from Al-Mg alloy AA5056, produced by friction stir welding along and across the workpiece rolling direction. The tests show that the variation of parameters results in the formation of a complex structure, which is determined by the contribution of both mechanical and thermal components. Depending on the rolling direction, the welded joint has different mechanical properties under identical conditions. In the case of the rolling direction coinciding with the friction stir welding direction, the strongest welded joint has the ultimate tensile strength of 328 MPa, which is equal to 98% of the base metal strength. In case of welding in the transverse direction, the ultimate tensile strength of the joint exceeds those of the base metal by 8 MPa and is equal to 333 MPa. According to the conducted experiments it was proved that the structure and strength of friction stir welded joints depends on the workpiece rolling direction, which implies different welding parameters for these cases. [ABSTRACT FROM AUTHOR]

In this work the study of the friction stir welding process of 2 mm thick aluminum alloy AA2024 sheets cut along and across the rolling direction was carried out. The obtained results show that the rolling direction of AA2024 sheet workpieces has a significant effect on the selection of optimal welding modes. It is revealed that at welding across the rolling direction it is possible to achieve the highest values of the ultimate tensile strength in a rather wide range of modes. [ABSTRACT FROM AUTHOR]

In this paper, regularities of the friction stir welding process parameters influence on mechanical properties of welded joints of different thicknesses are investigated. Joints were produced using the same type of tools with a screw-shaped pin. The tests show different dependencies of the joint mechanical behavior on the welding parameters. 2-mm-thick samples are characterized by high values of the ultimate tensile strength and a small variation of those when changing parameters. 10-mm-thick samples are characterized by a lower ultimate tensile strength and a greater variation at changing process parameters. [ABSTRACT FROM AUTHOR]