Diamond Film Generation from a Combustion Jet

该项目旨在开发一种燃烧-火焰生产金刚石薄膜的方法；这种方法具有在复杂形状上沉积大面积薄膜的潜力。在这项工作中，火焰将被支撑在燃烧室中，随后产品火焰气体通过会聚-发散喷嘴膨胀，形成超音速射流，该射流将直接对着衬底沉积所需的薄膜。这种方法有可能通过控制化学反应和传输现象来缓解以前与金刚石膜沉积相关的问题，例如均匀性差和高水平的颗粒杂质，从而导致在生产高质量金刚石膜时有效和均匀地利用燃烧产生的活性物质。这种方法所涉及的基本原则是：隔离富燃料燃烧产物云的活性部分（其中含有导致金刚石沉积的高水平物种）；通过喷嘴的快速膨胀过程将云中的化学物质冻结；将这种“冻结”的气流迅速输送到表面进行涂覆；在运输过程中以最佳方式修改均匀性/成分/温度；并在衬底表面建立一个薄的、均匀的边界层，活性物质可以穿过该边界层扩散到生长的金刚石膜上。应用燃烧生成的金刚石薄膜的拟议方法将对潜在的数十亿美元市场产生重大影响。一旦完善，这项新技术将提供一种实用、便携、低成本的方法，将金刚石涂层应用于各种材料，如机床和电子零件。

This project is aimed at development of a method for combustion- flame production of diamond films; this method has the potential for deposition of large area films on complex shapes. In this work, flames will be supported in a combustion chamber wivh subsequent expansion of the product flame gases through a converging-diverging nozzle to form a supersonic jet which will be directed against a substrate for deposition of the desired films. This approach has the potential to mitigate previous problems associated with diamond-film deposition such as poor uniformity and high levels of grain impurities via control of the chemical reactions and transport phenomena, thus leading to efficient and uniform utilization of the combustion-generated active species in production of high-quality diamond films. The basic principles involved in this approach are: isolate the active portion of the fuel-rich combustion product cloud (which contains high levels of species which lead to diamond deposition); freeze the chemistry in that cloud through the rapid nozzle expansion process; transport this "frozen" stream rapidly to the surface to be coated; modify the uniformity/composition/temperature in an optimum fashion in transit; and establish a thin, uniform boundary layer at the substrate surface across which the active species can diffuse to strike the growing diamond film. The proposed method for applying combustion-generated diamond films will significantly impact a potential billion dollar market. When perfected, this new technique will provide a practical, portable, low-cost method of applying diamond coatings to materials as diverse as machine tools and electronic parts.