Nd∶YAG脉冲激光打黑Al99.7铝机理研究

Research on mechanism of blackening Al99.7 aluminium by Nd ∶ YAG laser

调节Nd∶YAG脉冲激光器标刻参数在Al99.7铝表面可以获得白、灰、黑三种不同颜色深度的图形。为揭示激光打黑机理,使用分光光度计对样本表面光谱反射率进行了测定;使用扫描电子显微镜、能谱分析仪对标刻表面进行了观察分析。发现各样本灰度与光谱反射率变化关系对应一致,微观组织形貌差别大。富集有微米孔洞及纳米絮状物的样本表面反射率最低颜色最深,表明激光能量诱导产生的表面微纳米结构降低可见光范围光谱反射率是使标刻图形呈色的主要原因。

Three different scale color graphics(white,gray,b lack)on A199.7aluminum surface can be obtained by tuning the Nd:YAG pulse laser marking parameters.In order to study the mechanism of laser blackening,the spectral reflectivity of the samples was measured by spectrophotometer.The surface marked by the laser was analyzed by scanning electron microscopy and energy dispersive spectroscopy.It was found that the change rule of gray scale was consistent with that of the spectral reflectivity,but the microscopic morphologies are different greatly,and surface reflectivity of the sample with micron-scale pores and nano-scale floe is the lowest and its color is the deepest.The results show that the micro-and nanoscale structure on the surface induced by laser energy can reduce spectral reflectance within the visible range,and it is the main reason for marking graphs to appear color.