Abstract：
Nanosecond laser cleaning effectively removes oxide film and dirt from the surface of aluminum body parts for rail transit, as well as improving surface properties. The effect of laser cleaning on the quality of weld was studied in detail for different scanning frequencies and cleaning speeds. The effect of post-weld laser cleaning on weld quality was investigated. After laser cleaning at different parameters, the surface oxygen content was decreased and the surface roughness and surface hardness were increased. Variation of surface oxygen content was related to energy density and spot density. The lowest oxygen content was obtained at 150 W, 100 Hz and 0.8 m/min. Laser-generated craters changed surface morphology and improved surface roughness. The mechanical properties of the welded joints were slightly improved, which relates to a decrease in porosity. The minimum porosity of the laser-cleaned weld was 0.021%. This work provides new ideas for the nanosecond laser cleaning of aluminum alloy and its welding properties.
摘要：
纳秒激光清洗有效去除轨道交通用铝车身零件表面的氧化膜和污垢，以及改善表面性能。详细研究了不同扫描频率和清洗速度下激光清洗对焊缝质量的影响。研究了焊后激光清洗对焊缝质量的影响。在不同参数的激光清洗后，表面氧含量降低，表面粗糙度和表面硬度增加。表面氧含量的变化与能量密度和斑点密度有关。在150W时获得最低的氧含量，100赫兹和0.8米/分钟。激光产生的陨石坑改变了表面形态并改善了表面粗糙度。焊接接头的力学性能略有改善，这与孔隙率的降低有关。激光清洗焊缝的最小孔隙率为0.021%。该工作为铝合金的纳秒激光清洗及其焊接性能提供了新思路。
