Microstructure Evolution in Dissimilar Friction Stir Weld Joints of Precipitation and Solution Hardening Aluminum Alloys

Abstract

AbstractWelding can be made human friendly by reducing its adverse effects or by using green processes such as friction stir welding. In this paper, precipitation hardening and solution hardening aluminum alloys AA7039 and AA5086 were friction stir welded to study the evolution of microstructure in developed dissimilar joints. Weld joints exhibited lamellar pattern, intercalation flow pattern and zones characteristics of friction stir welding. These well-developed microstructural features and absence of defects established the mixing of both the materials from faying edges in the stir region. The friction stir welding is viable technique for ecological welding of different hardening alloys AA7039 and AA5086 as it eliminates problems related to fusion welding of such alloys.KeywordsDissimilar weldingAluminum alloysPrecipitation and solution hardeningMaterial flowMicrostructureStir zone