General regularities of the microstructure formation during friction stir welding and sliding friction

A comparative metallographic analysis of the formation of the metal microstructure during sliding friction and friction stir welding is performed. It has been shown based on the example of a weld joint made of aluminum alloy fabricated by friction stir welding that the weld microstructure has all signs of the deformed layer of metal formed due to sliding friction, which is accompanied by the seizure of conjugated surfaces.