SBIR Phase I: Low-Cost Formation of Ultrahard Diamond-Like Coatings

超硬材料（UHM）具有许多优越的上级性能，使得它们作为工业材料非常理想。 不幸的是，这些材料，特别是所有材料中最硬的类金刚石材料，由于其低抗氧化性、低热稳定性和高成本而不能用于许多大批量应用中。 为此，需要具有相当或甚至上级性质的新的低成本UHM。 基于已知热力学和结构数据的计算预测，立方碳氮化物，α-C3 N4，将比金刚石更硬，更耐热氧化。 尽管研究人员在过去十年中取得了重大进展，但这种材料以及其他类似材料的纯相的形成尚未完成。在该项目中，Ultramet将使用新型化学气相沉积（CVD）工艺生产新型UHM，如α-C3 N4，立方碳氮化合物（立方C（HN）），以及由金属氮化物纳米晶体和非晶氮化硅（Si 3 N4）相组成的复合三元氮化物。 这种新的工艺，这是动力学驱动，允许形成各种各样的陶瓷材料在或接近室温。应用：建议的新型CVD工艺将产生新的UHMs，如α-C3 N4，立方C（HN），和复合三元氮化物/Si 3 N4相的硬度和氧化稳定性等于或超过立方氮化硼和金刚石。 新工艺将使这些新的UHMs以更低的成本生产，并在比当前UHMs更广泛的应用中使用。关键词：超硬材料，立方碳氮化物，立方碳氮化合物，三元金属氮化物，化学气相沉积，薄膜，超硬磨料

Ultrahard materials (UHM) possess many superior properties, making them highly desirable as industrial materials. Unfortunately, these materials, particularly the hardest of all, diamond-like materials, cannot be used in many high-volume applications due to their low oxidation resistance, low thermal stability, and high cost. For this reason, new, low-cost UHMs with comparable or even superior properties are required. Calculations based on known thermodynamic and structural data predict that cubic carbon nitride, alpha-C3N4, will be significantly harder and much more thermally oxidation-resistant than diamond. Despite significant progress made by researchers over the last decade, the formation of pure phases of this material, as well as others like it, has not as yet been accomplished. In the project, Ultramet will generate novel UHMs such as alpha-C3N4, cubic carbonazenide (cubic C(HN)), and composite ternary nitrides consisting of metal nitride nanocrystals and an amorphous silicon nitride (Si3N4) phase using a novel chemical vapor deposition (CVD)-based process. This new process, which is kinetically driven, allows the formation of a large variety of ceramic materials at or near room temperature.Applications: The proposed novel CVD processes will yield new UHMs such as alpha-C3N4, cubic C(HN), and composite ternary nitride/Si3N4 phases with hardness and oxidation stability equal to or exceeding those of cubic boron nitride and diamond. The new processes will allow these new UHMs to be produced at lower cost and used in a much wider range of applications than current UHMs.Keywords: ultrahard materials, cubic carbon nitride, cubic carbonazenide, ternary metal nitrides, chemical vapor deposition, thin films, superabrasives