Corrosion studies, parameter effects, and surface morphology of AA5052-AA6101T6 friction stir welded joints

Abstract

Traditional fusion welding is unsuitable for welding aluminum alloys because secondary brittle phases, porosity, and cracks are likely to form as the alloy solidifies. Friction stir welding (FRSTW), a new solid-state welding method, can join similar or dissimilar aluminium (ALU) alloys. In this study friction stir welded AA5052-AA6101T6 alloy samples were tested for corrosion characteristics. The microstructure and mechanical behavior of FRSW-welded AA5052-AA6101T6 ALU alloy joints were examined relative to input parameters. Microstructure reveals that welding speed and rotation-speed affect the weld microstructure analyzed sample welded areas. Twenty-nine samples were corrosion tested in 3.5 % NaCl, household water (880 ppm - SPM), 1 M H2SO4, 1 M NaOH and natural seawater for 72 h. Domestic salt water and acid medium showed better resistance to corrosion than alkaline and salt media. Impedance studies demonstrated slight anodic and cathodic potential changes after friction stir welding.