In Situ Monitoring of Cu/Al Laser Welding using Laser Induced Fluorescence

Published

September 10, 2020

Author(s)

Brian Simonds, Tran N. Tran, Paul A. Williams

Abstract

We investigate laser spot welding of 200 µm thick Cu and Al foils using laser-induced fluorescence (LIF). The key to strong Cu/Al welds is limited intermetallic compound formation through controlled molten metal interaction time. For laser lap welds, Cu in the vapor plume is indicative of the degree of Cu melting. LIF sensitively detects individual elements and is used to interrogate the vapor plume for the earliest evidence of Cu atoms. We perform welds across a wide range of laser power (3–8 kW) for a pulse duration of 2 ms. We qualitatively determine weld strength by mechanically pulling apart the samples. Temporally-resolved LIF signals, along with backscattered laser light monitoring, demonstrate Cu detection immediately upon Al penetration. We find that LIF can detect Cu even under laser power conditions too weak to create a strong weld, which suggests that LIF may be sensitive enough for real-time, in situ monitoring of Cu/Al laser welding.

Proceedings Title

Proceedia CIRP

Volume

94

Conference Dates

September 6-10, 2020

Conference Location

Fuerth

Conference Title

LANE 2020 - 11th CIRP Conference on Photonic Technologies

Pub Type

Conferences

Download Paper

https://doi.org/10.1016/j.procir.2020.09.088

Local Download

Citation

Simonds, B. , Tran, T. and Williams, P. (2020), In Situ Monitoring of Cu/Al Laser Welding using Laser Induced Fluorescence, Proceedia CIRP, Fuerth, -1, [online], https://doi.org/10.1016/j.procir.2020.09.088 (Accessed October 7, 2025)