SBIR Phase I: Nanostructured WC/Co Coatings for Enhanced Wear Resistance Applications

这个小企业创新研究（SBIR）第一阶段项目将证明在低温下将nc-WC/Co涂层沉积在高强度钢上的可行性，同时保持优异的耐磨性。纳米晶（nc）材料在提供结构材料方面具有巨大的潜力，与传统的粗粒度材料相比，具有显著的性能改进。喷涂成型nc-WC/Co的进展非常有限，使用热喷涂设备沉积这些耐磨涂层的尝试多次失败。这些高温工艺不适用于nc-WC/Co涂层，因为在喷涂沉积过程中，纳米wc颗粒的表面体积比很高，会导致严重的脱碳。该项目将通过整合两种新工艺来克服这一技术缺陷，一种是被称为动能金属化（KM）的固态喷涂工艺，另一种是被称为综合机械和热活化（IMTA）的纳米晶粉末工艺。通过IMTA工艺生产的纳米晶WC/Co粉末将使用低温KM工艺沉积在高强度钢上。预计该技术一旦开发出来，将为金属部件和硬面涂层提供比目前传统的粗粒度涂层具有显著性能改进的材料。这项技术的广泛影响可能是改善航空航天和陆基燃气涡轮发动机的纳米晶体涂层，以及每年超过10亿美元的飞机执行器市场。针对这些市场的所有OEM和军事维修厂都在积极寻求替代涂层，以取代与硬铬涂层相关的对环境有害的工艺。除了航空航天市场，纳米晶涂层还将在食品加工、采矿、机械加工、基础设施和运输行业中得到许多应用，在这些行业中，具有改进耐磨性的硬面涂层将延长工具和设备的使用寿命，同时减少化学污染。

This Small Business Innovation Research (SBIR) Phase I project will demonstrate the feasibility of depositing nc-WC/Co coatings onto high-strength steels at low temperatures while retaining superior wear resistance properties. Nanocrystalline (nc) materials have enormous potential to provide structural materials with significant property improvements over conventional coarse-grained counterparts. Progress in spray forming nc-WC/Co has been very limited with numerous unsuccessful attempts to deposit these wear resistant coatings using thermal spray equipment. These high-temperature processes are not applicable for nc-WC/Co coatings because of severe decarburization during spray deposition, owing to the high surface-to-volume ratio of nano-WC grains. This technical deficiency will be overcome in this project by integrating two novel processes, one being a solid-state spray process called Kinetic Metallization (KM) and the other a nanocrystalline powder process known as Integrated Mechanical and Thermal Activation (IMTA). Nanocrystalline WC/Co powders produced by the IMTA process will be deposited onto high-strength steels using the low temperature KM process. It is anticipated that the technology, once developed, will provide metallic components and hard-face coatings with significant property improvements over today's conventional coarse-grained counterparts. The broader impact from this technology could be improved nanocrystalline coatings in aerospace and land-based gas turbine engines and aircraft actuator markets exceeds one billion dollars annually. All of the OEM and military repair depots for these markets are actively seeking alternative coatings to replace the environmentally hazardous processes associated with hard chrome coatings. In addition to the aerospace markets, nanocrystalline coatings will find many applications in the food processing, mining, machining, infrastructure, and transportation industries where hardface coatings with improved wear resistance will extend the life of tools and equipment while reducing chemical pollution.