脉冲激光对6106铝合金表面形貌及氧含量的影响

研究了脉冲激光清洗在不同的清洗速度以及不同的脉冲重复频率下铝合金表面形貌以及表面氧元素含量的影响。试验结果表明，在清洗速度较低时(0.1～0.6 m/min)，铝合金激光清洗过的表面呈溅射重叠的状态，当清洗速度大于0.8 m/min时，脉冲激光在铝合金表面的形成的冲击坑逐渐变得分散、独立；铝合金表面氧元素整体的含量随清洗速度的增减呈先下降后增加的趋势，在清洗速度较小或者较大时，氧元素含量均接近母材表面氧元素含量水平，氧元素含量分布具有明显的区域性，脉冲激光冲击坑的位置氧元素含量明显高于周围未冲击位置。随脉冲重复频率的增加，铝合金表面形貌由独立冲击坑逐渐过渡为溅射重叠的状态，表面氧元素整体含量明显下降，约为母材氧含量的1/2,氧元素的分布也逐渐变为弥散。

Effect of pulse laser on surface morphology and oxygen content of aluminum alloy

The effects of pulse laser cleaning on the surface morphology and oxygen content of aluminum alloy at different cleaning speeds and pulse repetition frequencies were studied.The results show that with lower cleaning speeds(0.1-0.6 m/min),the surface of aluminum alloy cleaned by pulse laser is in the state of sputtering and overlap.When the cleaning speed is greater than 0.8 m/min,the crater formed by the pulsed laser becomes dispersed and independent;The content of oxygen element on the surface of aluminum alloy decreases first and then increases with the increase of the cleaning speed.When the cleaning speed is low or high,the content of oxygen element is close to the level of oxygen element on the surface of base metal.The distribution of oxygen element content has obvious regionality,and the oxygen content in the impact crater of pulsed laser is obviously higher than that in the surrounding non-impact location.With the increase of pulse repetition frequency,the surface morphology of aluminum alloy gradually changes from independent impact crater to sputtering overlap.The content of oxygen on the surface decreases significantly,which is about 1/2 of the oxygen content in the base metal,and the distribution of oxygen elements also gradually becomes diffuse.