火焰结构对YT14硬质合金表面沉积碳产物的影响

Effects of Flame Structure on the Carbon Products Deposited on YT14 Harmetal

采用氧-乙炔火焰法在YT14硬质合金表面沉积碳纳米材料,借助扫描电子显微镜和激光拉曼光谱仪对火焰沉积碳产物的形貌和结构进行了表征,并分析研究了火焰结构对沉积产物的影响。结果表明,氧-乙炔火焰的内焰长度、基体在火焰中所处位置和火焰沉积温度不同,火焰中的碳氢基团和活性质点等气相成分种类、浓度及分布梯度相应发生了变化,所获得的火焰沉积产物和分布状况也不一样。当内焰长度调至50 mm、基体-喷嘴距离为30 mm、沉积温度为850℃时,沉积产物主要为"菜花状"的类金刚石碳;当内焰长度调至70 mm、基体-喷嘴距离为40 mm、沉积温度为750℃时,沉积产物主要为"颗粒状"的纳米针状碳聚集体。

Oxygen-acetylene （02-C2H2） flame was used to synthesize carbon nanomaterials on the surface of YT14 hardmetals. The morphology and structure of the deposited products together with the effects of the flame structure on the deposited products were investigated by scanning electron microscope and Raman spectroscope, respectively. The results show that the deposited products vary with factors such as the inner flame length, the substrate position in the flame and the flame-deposited temperature, which affect the species and concentration distribution of C-H radicals and active particles. The main products are the cauliflower-shaped diamond-like carbon in the flame with the inner flame length of 50 mm and the distance between the substrate and the nozzle of 30 mm at 850 ℃, while particles aggregated with nanocarbon needles are deposited in the flame with the inner flame length of 70 mm and the distance between the substrate and the nozzle of 40 mm at 750 ℃.