Study of laser surface texturing of 6061 aluminium with thermal assistance

摘要

Laser surface texturing (LST) on 6061 aluminium with thermal assistance was carried out. The mechanisms of LST under various offset temperatures were expounded and clarified. The experimental results demonstrate that the offset temperature during laser processing has a significant influence on the formation of micro-features, evolution of oxidation reactions, surface morphology, resolidification characteristics and surface components. With the aid of an offset temperature, the interaction between a laser and the target materials can be significantly enhanced; thus, physical ablation and modification for LST can be achieved effectively. The ablation efficiency with an offset temperature of 300 degrees C can be up to approximately four times higher than that at room temperature, i.e. 25 degrees C. Moreover, the efficiency of surface texturing to realize a darkening effect on the sample surface with a temperature of 300 degrees C (200 mu m s(-1)) is approximately four times faster than that with a temperature of 25 degrees C (50 mu m s(-1)). Furthermore, the ablation threshold on 6061 aluminium with respect to different offset temperatures was determined. The derived result suggests that compared to normal LST, the ablation threshold can be reduced during thermal-assisted laser texturing.

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