Metallurgical and mechanical investigation on FSSWed dissimilar aluminum alloy

Abstract

The present work is the novel examination of influence of welding process parameters and material flow on the mechanical and microstructural characteristics during the FSSW of dissimilar AA2024/AA7075 joint were evaluated and compared with similar AA2024/AA2024 and similar AA7075/AA7075 FSSW joints. The microstructural and physical properties of two aluminum alloy joined through friction stir spot welding (FSSW) were examined. The aluminum alloys namely AA2024-T3 and AA7075-T6 were selected for the investigation owing to their typical and potential applications in aeronautical industry. The input parameters were tool rotational speed, plunge depth and dwell time (TRS 1800 rpm, 3.3 mm plunge depth and 45 s dwell time) were utilized. The microstructure of the welded specimen was investigated by scanning electron microscope and their chemical compositions were analyzed by energy-dispersive X-ray spectroscopy. The physical properties were investigated by Vickers microhardness survey and the specimen strength evaluated by tensile tests. The experimental investigation revealed the influence of the tool pin penetration and frictional heat on the microstructure, distribution of the grain structure affecting the microhardness and the tensile properties of the dissimilar joint.

Keywords

• Aluminum alloys
• Friction stir spot welding
• AA2024-T3
• AA7075-T6
• Dissimilar joint
• Microhardness