Exploring a novel chamfered tool design for short duration refill friction stir spot welds of high strength aluminium

Draper, Jonathan and Fritsche, Sebastian and de Traglia Amancio-Filho, Sergio and Galloway, Alexander and Toumpis, Athanasios (2024) Exploring a novel chamfered tool design for short duration refill friction stir spot welds of high strength aluminium. The International Journal of Advanced Manufacturing Technology, 131 (12). pp. 5867-5879. ISSN 1433-3015 (https://doi.org/10.1007/s00170-024-13336-x)

[thumbnail of Draper-etal-IJAMT-2024-Exploring-a-novel-chamfered-tool-design-for-short]
Preview
Text. Filename: Draper-etal-IJAMT-2024-Exploring-a-novel-chamfered-tool-design-for-short.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo

Download (6MB)| Preview

Abstract

This work investigates refill friction stir spot welded joints of AA2024-T3 aluminium alloy, produced with short welding times between 3 s and 0.75 s. A novel tool geometry that incorporates a chamfer on the inner edge of the shoulder tip is investigated as a means of improving joint quality at short welding times by easing material flow during the refill stage. The influence of shoulder design on weld microstructure, defect formation, material flow, and mechanical properties was assessed. When compared with a standard shoulder geometry, it was found that the introduction of a chamfer on the inner tip edge improved material flow during the refill stage and led to improved material mixing at the weld periphery. The formation of voids in the region of the weld periphery was eliminated and tensile lap-shear strength of the welded joints was increased by 19% to 7.2 kN, and 27% to 8.16 kN, for 0.75 s and 1.5 s duration welds, respectively.