Designing Ultra-hard Coatings of Q-carbon and Diamond Related Materials

非技术描述：超硬保护涂层在从微电子封装到石油和天然气提取所需的切割工具以及高速加工等应用中都是至关重要的。性能的改善与防护涂层的硬度提高直接相关。这项提议专注于超硬材料的设计和合成，力争比钻石更硬--钻石是目前已知的最硬的材料。通过使用一种基于快速激光熔化和淬火的新方法，有可能产生更硬的钻石或新的碳的Q相。由于这一过程可以在环境温度和压力下进行，因此大大减少了Q-碳和钻石相关材料的能源使用和制造。这项研究正在与课程开发和相关的教育活动相结合，如M.S.Nano计划。该提案涉及与ORNL、Kopin Corporation和NC A&A；T合作培训研究生和本科生，以吸引少数族裔学生进入研究生学习。技术细节：采用纳秒激光熔化碳膜，过冷态快速淬火，合成了金刚石和Q相相关材料。过冷度决定了这种直接转化为钻石或Q-碳或两者的混合物。通过模拟来了解激光与固体的相互作用以及硬度与原子数密度之间的关系。在本项目中，通过控制激光、薄膜和蓝宝石衬底的变量，合成了不同的Q-碳和金刚石混合物。这些阶段的特点是使用高分辨率电子显微镜、电子能量损失光谱和拉曼技术，并建立了与增强的硬度和韧性的直接关联。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL DESCRIPTION: Ultrahard protective coatings are critical in applications ranging from microelectronics packaging to cutting tools needed for oil and gas extraction and high-speed machining. Performance improvement directly scales with the hardness enhancement of protective coatings. This proposal focuses on design and synthesis of ultrahard materials, striving to be harder than diamond — the hardest material known so far. By using a novel approach based upon rapid laser melting and quenching, it is possible to create diamond or new Q- phases of carbon which are significantly harder. Since this process can be performed at ambient temperatures and pressures, there is a significant reduction in energy usage and manufacturing of Q-carbon and diamond-related materials. This research is being integrated with the curriculum development and related educational activities, such as M.S. Nano program. The proposal addresses training of graduate and undergraduate students in collaboration with ORNL, Kopin Corporation and NC A&T to attract minority students into the graduate studies. TECHNICAL DETAILS: Diamond and Q-phase related materials are synthesized by nanosecond laser melting of carbon films and rapid quenching from the undercooled state. The degree of undercooling determines this direct conversion into diamond or Q-carbon or a mixture of the two. Modeling is carried out to understand laser-solid interactions and correlations between hardness and number density of atoms. In this project, different Q-carbon and diamond mixtures are synthesized by controlling laser, film and sapphire substrate variables. These phases are characterized by using high-resolution electron microscopy, electron-energy-loss spectroscopy and Raman techniques, and direct correlations with enhanced hardness and toughness established.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.