SBIR Phase I: High Pressure Sintering of Nanocrystalline Diamond Compacts

这个小企业创新研究第一阶段项目将解决“无粘结剂”纳米晶金刚石压片（ndc）的烧结问题。烧结将采用先进的高压/高温合成方法，在1800 oK下的能力为15 GPa。目前。聚晶金刚石压片（PDCs）是由20-70微米大小的金刚石粉末通过高压压实方法，使用金属粘合剂（Co, Si Ni）制成的商业产品。金属粘结剂的使用降低了压坯的热稳定性，而使用大的金刚石粉末颗粒则降低了韧性和延展性。这限制了配电箱的应用。该项目将开发一种经济的方法来制造纳米晶金刚石压片（ndc），不需要任何粘合剂，从5纳米的金刚石颗粒粉末。材料的硬度和韧性应与天然形成的聚晶金刚石相匹配。超细晶金刚石压块是精密制造工具的候选材料，可用于硬质材料的高速加工和制造。该项目将证明使用高纯度纳米金刚石粉作为起始材料生产ndc测试样品的可行性，以及我们内部用于粉末压实的超高压装置。该项目将确定NDC样品的物理和机械性能。常规大批量生产无粘结剂纳米晶金刚石片将显著提高刀具的高温稳定性和精密性能。

This Small Business Innovative Research Phase I project will address sintering of `binderless` Nanocrystalline Diamond Compacts (NDCs). Sintering will be performed using an advanced high pressure/high temperature synthesis method with capabilities of 15 GPa at 1800 oK. Currently. Polycrystalline Diamond Compacts (PDCs) are produced commercially from 20-70 micron size diamond powder by high pressure compaction methods, using metal binders (Co, Si Ni). Use of the metal binder reduces the thermal stability of the compacts, while use of large diamond powder particles reduces the toughness and ductility. This limits the applications for the PDCs. This project will develop an economical method for fabricating Nanocrystalline Diamond Compacts (NDCs), without any binder from 5 nm diamond particle powders. The hardness and toughness of the material should match those of naturally formed polycrystalline diamond - `carbonado`. The ultra-fine grained diamond compacts are candidate materials for precision manufacturing tools, which can be used for high rate machining and fabrication of hard materials. The project will demonstrate the feasibility of producing test samples of NDCs using highly purified nano-diamond powder as starting material, and our in-house ultrahigh pressure unit for powder compaction purposes. This project will determine the physical and mechanical properties of the NDC samples. Routine production of large volumes of binderless nanocrystalline diamond compacts will significantly improve the high temperature stability and precision performance of cutting tools.