飞秒激光刻蚀对纳米金刚石薄膜表面微观特性的影响  

Effects of Femtosecond Laser Ablation on Surface Micro-properties of Nano-crystalline Diamond Coating

作　　者：马玉平 魏超 张遥 李翔 陈雪辉 MA Yuping;WEI Chao;ZHANG Yao;LI Xiang;CHEN Xuehui(School of Mechanical and Electrical Engineering,Anhui Jianzhu University,Hefei 230601,China)

机构地区：[1]安徽建筑大学机械与电气工程学院

出　　处：《中国表面工程》2019年第3期1-10,共10页China Surface Engineering

基　　金：国家自然科学基金(51375011);安徽省自然科学基金(1208085ME63,1908085ME129);安徽省教育厅自然科学基金(KJ2015A050,KJ2015A013)~~

摘　　要：利用飞秒激光对纳米金刚石涂层进行刻蚀试验,通过改变激光的重复频率,输出功率以及焦点扫描速度,研究不同的激光加工参数对金刚石涂层烧蚀结果的影响。利用白光干涉仪器、SEM、拉曼光谱仪研究了飞秒激光刻蚀后涂层表面微观粗糙度、微观形貌以及碳相结构变化。采用面积推算法计算出扫描速度1 mm/s,有效脉冲数为90时的烧蚀阈值。结果表明:金刚石涂层表面飞秒激光诱导的条纹状结构周期(LIPSS)接近飞秒激光波长,改变飞秒激光重复频率对涂层表面形貌修饰影响不大;由于烧蚀饱和作用,飞秒激光功率增加至80 mW过程中涂层表面微观粗糙度持续减小随后维持在325 nm左右;激光扫描速度的增大可使LIPSS特征消失,当扫描速度增加至1.4 mm/s后,涂层表面微观粗糙度不再继续降低而是随着速度的增大而增大。激光诱导的金刚石涂层表面石墨化程度越高,涂层表面微观粗糙度则越低;当有效脉冲数为90时纳米金刚石薄膜的飞秒激光烧蚀阈值为0.138 J/cm2。In order to study the effect of different femtosecond(fs)laser processing parameters on nanocrystalline(NC)CVD diamond coating deposited on cemented carbide substrates,the ablation tests of NC diamond coating were carried out with different femtosecond laser power,repetition rates and scanning velocities.The surface roughness,morphology and carbon phase structure of the coatings were analyzed by white-light interferometer,SEM,Raman spectrometer and other testing instruments.The ablation threshold of the coating at 90 pulses was calculated by numerical simulation.Experimental results show that the period of femtosecond laser induced periodical surface structure(LIPSS)fabricated on NC diamond coating is close to the laser wavelength.The variation of repetition rate has little effect on the properties of the coatings.The surface roughness of the coating decreases continuously as the femtosecond laser power increases from 50 mW to 80 mW and then keeps about 325 nm over 80 mW due to ablation saturation.The feature of LIPSS diminishes gradually as scanning velocities increases.When the scanning velocity reaches about 1.4 mm/s,the surface roughness stops decreasing,and instead,it goes up with the increase of the scanning velocity.The higher the degree of graphitization induced by laser,the lower the surface roughness of the diamond coating.The threshold of fs laser ablation of the NC diamond coating at 90 effective pulses is 0.138 J/cm2.

关 键 词：飞秒激光 纳米金刚石涂层 粗糙度 石墨化 烧蚀阈值 

分 类 号：TG174.44[金属学及工艺—金属表面处理] TN305.7[金属学及工艺—金属学]