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油气开采和高速加工所需的切削工具等应用中至关重要。性能的提高直接与保护涂层硬度的提高成正比。这一提议的重点是设计和合成超硬材料，力求比迄今为止已知的最硬材料——金刚石还要硬。通过使用一种基于快速激光熔化和淬火的新方法，可以创建金刚石或新的Q相碳，它们明显更硬。由于该过程可以在环境温度和压力下进行，因此大大减少了q -碳和金刚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.纳米项目。该提案涉及与ORNL、Kopin Corporation和NC A&amp；T合作培养研究生和本科生，以吸引少数民族学生进入研究生学习。技术细节：金刚石和q相相关材料是通过纳秒激光熔化碳膜并从过冷状态快速淬火而合成的。过冷的程度决定了这种直接转化为金刚石或q -碳或两者的混合物。模拟是为了理解激光与固体的相互作用以及硬度和原子数密度之间的关系。在这个项目中，通过控制激光、薄膜和蓝宝石衬底变量，合成了不同的q -碳和金刚石混合物。这些相通过高分辨率电子显微镜、电子能量损失光谱和拉曼技术进行表征，并与硬度和韧性的增强直接相关。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.