不同材料的准分子激光修饰表面形貌的分形表征

采用准分子激光加工方法,在相同的工艺参数下加工了脆性材料（A1203陶瓷）和塑性材料（不锈钢、Q235钢）试件.采用分形理论研究了准分子激光加工的不同材料表面的分形特征,通过结构函数法计算了表面微观形貌的分形维数.结果表明：准分子激光加工的不同材料的表面形貌具有不同的分形特性,在相同的加工条件下A1203陶瓷材料表面的分形维数大于不锈钢、Q235钢等塑性材料表面的分形维数,表明脆性材料和塑性材料具有不同的准分子激光加工属性;准分子激光加工表面的分形维数随着激光扫描速度的增大而减小,随放大器电压和脉冲频率的增大而增大,表明可以通过改变加工参数得到不同的分形维数表面.

Fractal Characterization of Different Materials Processed by Excimer Laser

On the same processing parameters,some materials which are Al2O3 ceramic, stainless steel, and Q235 steel were processed by excimer laser. The fractal characteristics of surfaces of varying materials were studied with fractal theory, and fractal dimensions of these surface profiles were computed with structural function method. The results show that there are differences in the surface topography of varying materials processed by excimer laser, and the fractal dimension of Alz 03 ceramic surface is larger than that of stainless steel and Q235 materials surfaces. The fractal dimension is relation to varying materials as well as processing parameters. For example, the fractal dimension decreases with the growing of excimer laser scanning speed, and increases with the growing of the amplifier voltage and pulse frequency of excimer laser instrument. Therefore,fractal dimension can be used to character the processing surfaces of varving rnaterials.