Results

Results Paper Published - 22 May 2026

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* Opens Warwick University website

Coupling ultrasound-induced nucleation mechanism and ring-mode beam shaping in laser welded AA6063 extrusions

Pamarthi, Venkat Vivek, Hoque, Samiul, Carr, Phil, Kotadia, Hiren R. and Franciosa, Pasquale (2026) Coupling ultrasound-induced nucleation mechanism and ring-mode beam shaping in laser welded AA6063 extrusions. In: 14th CIRP Conference on Photonic Technologies, Erlangen, Germany, 21-25 Sep 2026. Published in: Procedia CIRP ISSN 2212-8271. (In Press)

Abstract

This study investigates the coupling effects of Adjustable Ring-Mode (ARM) beam shaping and contact-based ultrasound (20 and 40 kHz) on the weldability of AA6063 extrusions. The results highlight that weld mechanical performance is governed by the combined influence of porosity, microcracks and grain structure rather than grain refinement alone. Application of low-frequency ultrasound (20 kHz) significantly reduced pore fraction, leading to improved tensile strength by 34.6% relative to the baseline condition (core-only beam without ultrasound treatment). In contrast, high-frequency ultrasound (40 kHz) produced in general the highest equiaxed grain fraction but introduced increased pore formation and microcracks, resulting in reduced tensile performance, especially at the 40 kHz in conjunction with the core-ring beam configuration. Overall, the most effective processing conditions were identified as the core-only with low-frequency 20 kHz ultrasound, and core–ring beam alone without ultrasound.

Report on process simulation and validation - January 2026

The Soni-Shape-Laser project has successfully completed half the project (of 2 years) including all the simulation program, with the ultra-sonic excitation and the beam shaping variations. Some encouraging results were found with the 20kHz frequency when placed just 90mm away from the weld. The EBSD analysis ( to the left of each diagram) shows marked improvement to the grain structure of the weld when welded with the ultrasound as mentioned. The simulation pattern (to the right) of the diagram shows the temperature variations live in the weld and how the ultrasound changes the fluid flow from the baseline example. A paper has been written and will be published after reviewing later this spring 2026.