摘要
研究了直径尺度为50μm的片状石墨,在不同激光能量密度的辐照下,原位生成纳米粒状石墨的微观结构及形貌,初步探讨了激光辐照参数与微米石墨原位生成纳米石墨之间的规律。采用高分辨透射电镜(HRTEM)、扫描电子显微镜(SEM)和X射线衍射(XRD)对制备的纳米石墨的晶体结构及显微形貌进行了测试、分析。试验结果表明:在激光能量密度为5.00 kJ/cm^2时,试样由微米片状石墨原位生成分散性较好的、平均粒径为245 nm的球状石墨;在激光能量密度提高到6.25 kJ/cm^2时,样品原位生成双向生长的椭球状石墨,有团聚现象产生,平均粒径为240 nm;在激光能量密度达到12.50 kJ/cm^2时,微米片状石墨转变成大量的球状石墨,平均粒径为61.5 nm;在激光能量密度继续增加到13.75 kJ/cm^2时,产物呈现小颗粒附着在大颗粒上的现象,粒径范围为150～500 nm,平均粒径达280 nm。
The microstructure and morphology of nano-granular graphite in situ formed on 50 μm flake micro-graphite irradiated by different energy density laser were investigated. The rules between process parameters of laser irradiation and in situ formation of nano-graphite on micro-graphite were preliminarily discussed. The morphology and microstructure of samples were studied by scanning electron microscope(SEM), and the crystallinity and microstructure of samples were studied by high resolution transmission electron microscopy(HRTEM) and X-ray diffraction(XRD). The experimental results show that the flake micro-graphite is changed into a large number of spheroidal graphite whose average size is245 nm when the power density is 5.00 k J/cm^2. When the laser energy density reachs to 6.25 kJ/cm^2, the spherical graphite whose average size is 240 nm with agglomerate phenomenon is found. After the laser energy density increases to 12.50 kJ/cm^2, samples present as form of spherical particle whose average size is 61.5 nm. When the power density is 13.75 kJ/cm^2, the irradiated resultants of flake micro-graphite show a phenomenon that small particles attach to large particles, the size of irradiated resultants have a large range from 150 nm to 280 nm.
作者
刘孝谦
骆芳
杜琳琳
陆潇晓
Liu Xiaoqian;Luo Fang;Du Linlin;Lu Xiaoxiao(Institute of Laser Advanced Manufacturing, Zhejiang University of Technology, Hangzhou 310014, China;Zhejiang Provincial Collaborative Innovation Center of High-end Laser Manufacturing Equipment, Hangzhou 310014, China;College of Zhijiang, Zhejiang University of Technology. Hangzhou 310024, China;School of Materials and Environment Engineering, Hangzhou Dianzi University, Hangzhou 310018, China)
出处
《红外与激光工程》
EI
CSCD
北大核心
2019年第5期69-76,共8页
Infrared and Laser Engineering
基金
国家自然科学基金(51271170)
关键词
纳米石墨
激光辐照
晶体结构
微观形貌
nano-graphite
laser irradiation
crystal structure
microscopic morphology
