摘要
目的采用激光裂解聚二甲基硅氧烷先驱体(PDMS)法制备陶瓷涂层。方法在清洁的钢基体表面均匀涂覆PDMS溶液,恒温固化后得均匀有机涂层。用CO_2连续激光匀速扫描该涂层,裂解后得到陶瓷涂层。通过电子显微镜(SEM)、X射线衍射(XRD)和X射线光电子能谱(XPS)等手段,分析了激光裂解PDMS产物的组成与结构,研究了激光功率、激光扫描次数、扫描线速度等激光参数对PDMS陶瓷化的影响。结果较低激光功率(如700 W)、较少的扫描次数(如1次)和较大的扫描线速度(如18 mm/s)都会使制备的涂层表面层块状明显,孔隙较大,裂纹较多。较高的激光功率(如1000 W)、较多的扫描次数(如3次)和较小的扫描线速度(如10 mm/s)有利于涂层的层块结构消失,表面更趋于细化平整。结论激光功率、激光扫描次数、扫描线速度对聚二甲基硅氧烷的陶瓷化程度和晶态β-Si C的生成与相转变有很大影响。激光能量注入高时,聚二甲基硅氧烷吸收的激光能量多,陶瓷化比较彻底,但会使晶态β-Si C发生相变反应,生成非晶态α-Si C,不利于晶态β-Si C的形成。
The work aims to prepare ceramic coating via laser pyrolysis of polydimethylsiloxane （PDMS）. The PDMS solu- tion was uniformly coated on clean steel substrate and cured at constant temperature to obtain uniform organic coating. Then the organic coating was scanned with CO2 continuous laser to fabricate ceramic coating after pyrolysis. Composition and structure of the product obtained by laser pyrolysis of PDMS were analyzed, and effects of such laser parameters including laser power, laser scanning times and scanning linear velocity on ceramization of PDMS were studied by using scanned electron microscopy （SEM）, X-ray diffractometer （XRD） and X-ray photoelectron spectroscopy （XPS）. Lower laser power （eg. 700 W）, fewer scan- ning times （eg. 1 time） and higher scanning linear velocity （eg. 18 mm/s） would lead to more evident layer-mesostructure, more cracks and larger pores of the coating surface. In contrast, higher laser power （eg. 1000 W）, more scanning times （eg. 3 times） and lower scanning linear velocity （eg. 10 mm/s） were conductive to remove the layer-mesostructure, and the coating surfacetended to be more refined and flat. The laser power, laser scanning times and scanning linear velocity have great influence on ceramization degree of polydimethylsiloxane, and formation and phase transition of crystalline β-SIC. High laser energy pro- vides enables the polydimethylsiloxane to absorb more laser energy, hence leading to more thorough eeramization of PDMS, nevertheless it may cause the phase transition of crystalline β-SiC into amorphous α-SiC, which is not conducive to the forma- tion of crystalline ^-SiC.
出处
《表面技术》
EI
CAS
CSCD
北大核心
2017年第10期120-127,共8页
Surface Technology
基金
国家自然科学基金(51575526)~~
关键词
激光裂解
硅氧烷先驱体
陶瓷涂层
陶瓷化机理
laser pyrolysis
siloxane precursor
ceramic coating
ceraraization mechanism
