Research Initiation Award: Development of Diamond Growth Techniques Using Oxyacetylene Combustion Flame Method

9309669张这项研究是关于金刚石生长技术的发展，其中采用了氧乙炔燃烧合成法。该项目包括设计和建造一台金刚石生长装置，该装置包括一个氧乙炔焊枪，配备一个铜焊或切割喷嘴，两个质量流量控制器和一个质量流量编程器等，以及在各种刀具材料上生长金刚石薄膜。最终目标是将研究成果应用于工业情况，即在各种刀具上生产可行、廉价的金刚石涂层技术，用于制造应用。目前，金刚石相成核和金刚石薄膜与基材粘结的机理还不清楚，这使得这项技术的应用非常有限。本研究将探讨金刚石生长过程中所涉及的金刚石相成核机制。调查将包括在不同条件下对衬底表面进行预处理，使用电子顺磁共振(EPR)技术检测处理后的衬底上的悬挂键密度，以及使用残余气体分析技术分析乙炔火焰滞止区内外的前体气体。通过对前驱体气体化学物种和衬底悬键密度的研究，研究金刚石相成核机理。参数研究将朝着提高金刚石相成核密度和改善金刚石薄膜质量的方向发展。研究人员将寻求对这些机理的基本了解，这将促进氧-乙炔燃烧合成金刚石薄膜在工业应用中的应用。

9309669 Zhang This research concerns development of diamond growth techniques in which the oxyacetylene combustion synthesis method is employed. The project involves design and construction of a diamond growth apparatus consisting of an oxyacetylene welding torch, fitted with a brazing or cutting nozzle, two mass flow controllers and a mass flow programmer, etc., and growth of diamond films on a variety of cutting tool materials. The ultimate goal is to apply the research findings to an industrial situation, namely to produce viable, inexpensive techniques of diamond coating on various cutting tools for manufacturing applications. Currently, the mechanisms for nucleation of the diamond phase and for adherent bonding of diamond film to the substrate are not will understood, making the application of this technology very limited. The research will investigate the nucleation mechanisms of diamond phase involved in the diamond growth processes. The investigation will include pretreatment of substrate surfaces in various conditions, detection of dangling bond densities on the pre-treated substrate using the electron paramagnetic resonance (EPR) technique, and analysis of the precursor gas within and beyond stagnation zone of the acetylene flame using the residual gas analysis technique. Nucleation mechanisms of diamond phase will be researched by incorporating studies of chemical species of precursor gas and dangling bond densities of the substrate. Parametric studies will be towards enhancing nucleation density of diamond phase and improving quality of diamond films. The researcher will seek to develop a fundamental understanding of these mechanisms which will facilitate the application of oxyacetylene combustion synthesis of diamond films to industrial applications.