Application of Oscillating Laser in Aluminum And Dissimilar Material Welding

01. Introduction

Aluminum alloy and dissimilar metal composite welding offer significant advantages in improving the overall performance of welded joints. However, their inherent physical and chemical property differences often lead to weld performance deviations from design expectations. Oscillating laser welding technology, with its multi-parameter coordinated control capability, enables precise control over molten pool behavior by optimizing process parameters, effectively addressing the challenges of aluminum and dissimilar metal welding. This technology enhances cladding efficiency, promotes uniform material mixing, and optimizes defect suppression mechanisms, significantly improving welding quality. The energy distribution characteristics of the oscillating beam allow flexible adjustment of weld morphology, achieving coordinated control of a narrow heat-affected zone and a uniform microstructure.

02. Aluminum and Copper

Aluminum-copper welded joints exhibit corrosion resistance, high electrical conductivity, and lightweight properties. However, they face challenges in forming intermetallic compounds (IMCs). In an oscillating laser welding study of 0.2mm aluminum and 1.5mm copper (laser power: 525W, welding speed: 17mm/s, oscillation frequency: 600Hz, amplitude: 0.3mm), it was found that optimizing process parameters can control molten pool behavior and minimize IMC formation. The oscillating laser welding process effectively facilitates the mixing of aluminum (represented in red) and copper (represented in green) in the molten pool, thereby enhancing weld strength.

03. Aluminum and Aluminum

In a study on butt joint welding of 3mm thick 2A12-T4 and 6061-T6 aluminum alloys (laser power: 3400W, welding speed: 50mm/s, oscillation frequency: 0-500Hz, amplitude: 0.4-1.6mm), it was observed that the base materials contain different copper percentages (approximately 4.9% in 2A12 and 0.15% in 6061). Achieving ultra-high-strength welded joints requires uniform distribution of copper in the molten pool. As shown in Figure 2, in traditional laser welding, copper primarily migrates toward the 2A12 aluminum alloy. In oscillating laser welding, the beam oscillation and molten pool turbulence help push copper from the high-copper-content 2A12 aluminum alloy toward the low-copper-content 6061 aluminum alloy, ensuring a uniform copper distribution and enhancing weld strength.

04. Aluminum and Stainless Steel

In oscillating laser welding of stainless steel and 6061 aluminum alloy, different oscillation amplitudes were used. Experimental results indicated that increasing the oscillation amplitude improved the performance of Al/steel dissimilar welded joints. Simulations of the molten pool temperature field revealed that the oscillating laser beam disperses energy, and the diffused heat reduces interface element diffusion and lower aluminum plate melting. Consequently, IMC formation was suppressed, leading to improved tensile-shear strength of the welded joint.

05. Conclusion

Oscillating laser welding, through high-frequency beam oscillation and dynamic thermal input control, significantly enhances the quality of aluminum and dissimilar metal welding:

• Aluminum-copper welding suppresses brittle IMC formation.

• Aluminum-aluminum dissimilar joints achieve uniform copper distribution through laser oscillation and molten pool turbulence, improving weld strength.

• Aluminum-steel welding utilizes energy dispersion to reduce interface element diffusion, significantly increasing tensile load capacity.

This technology, with precise heat input control, defect suppression, and microstructure optimization, serves as a key process in high-demand fields such as electric vehicle batteries and aerospace lightweight structures, balancing efficiency and reliability.

**--Cite the article published by 高能束加工技术 on March 26, 2025, in the WeChat public account "High-Energy Beam Processing Technology and Applications."