自支撑金刚石膜冲蚀磨损研究

在研制的高压气动冲蚀磨损实验系统中对自支撑金刚石膜(抛光和未抛光)的冲蚀磨损进行了研究.比较了冲蚀磨料(SiO2,Al2O3,SiC和玻璃珠)、冲蚀角度、冲蚀速度,以及冲蚀时间对冲蚀磨损率的影响.利用扫描电子显微镜(SEM)观察了冲蚀磨损后金刚石膜表面形貌,对其进行了Raman光谱分析,并测定了抛光金刚石薄膜红外透过率的变化.结果表明,随冲蚀磨料硬度、冲蚀角度以及冲蚀速度的增加,自支撑金刚石膜的冲蚀磨损率增加.由于抛光和未抛光的金刚石薄膜表面形貌的差异,使得它们的冲蚀磨损率随冲蚀时间的变化过程不同.Raman光谱检测结果显示,由于冲蚀作用,金刚石膜表面部分碳的键合类型发生改变.冲蚀磨损使得抛光金刚石薄膜红外透过率降低,采用180目SiC磨料,在134 m/s的速度下冲蚀4 h,红外透过率降低约20%.

Investigation on the sand erosion of free-standing diamond films

By using a gas blasting erosion tester,sand erosion behavior of unpolished and polished free - standing diamond films were investigated. Different erodent,silicon dioxide,aluminum, silicon carbide and glass bead, were used. The effects of erosion time, impact angle and impact velocity on the erosion rate were examined. Erosion damages caused by solid particle impact were characterized by scanning electron microscopy and Raman spectroscopy. The change of infrared transmittance of polished free - standing diamond films was tested. The results indicated that the erosion rate increased with the increasing of erodent hardness, impact angle and impact velocity. Raman spectrum of eroded diamond films suggested that the bonding between carbon atoms was somehow modified by erosion. The infrared transmittance of polished free - standing diamond films decreased by 20% , after 4 hours erosion at 134 m/s impact speed with 180 mesh SiC.