Numerical and experimental investigation of heat transfer and flow in oscillating laser dual-wire deposition

Abstract

The oscillating laser heat source covers a large area, effectively reducing peak temperature and temperature gradient, while dual-wire additive manufacturing improves wire melting efficiency and forming quality. Therefore, this paper addresses the issues of low wire melting efficiency and poor forming quality in aluminum alloy wire melting additive manufacturing. Using 5A06 aluminum alloy as the research subject, a process combining oscillating laser and dual-wire techniques is proposed. Experimental and simulation analyses are conducted to evaluate this process, leading to the development of a coupled thermal-fluid model for the oscillating laser dual-wire additive manufacturing. Simulations of the temperature and flow fields are performed for various oscillation paths, frequencies, and amplitudes. The results demonstrate that, under the circular oscillation mode, the heat distribution within the molten pool is more uniform, the flow field remains stable, and the overall forming quality is superior. As the oscillation frequency increases, the width of the deposited layer decreases, while its height increases. Additionally, the melt pool's range, depth, and peak temperature exhibit a negative correlation with the oscillation frequency. Increasing the oscillation amplitude leads to a reduction in the melt pool's range, depth, and peak temperature, with the most stable flow and pool condition observed at an amplitude of 1.5 mm. This research provides both theoretical insight and guidance for the optimization of the oscillating laser dual-wire additive manufacturing process for aluminum alloys.