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

这个小型企业创新研究(SBIR)第一阶段项目将展示在低温下在高强度钢上沉积NC-WC/Co涂层的可行性，同时保持优异的耐磨性能。纳米晶(NC)材料在提供结构材料方面具有巨大的潜力，与传统的粗晶材料相比具有显著的性能改进。喷射成形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。由于纳米WC颗粒的比表面积大，在喷射沉积过程中会出现严重的脱碳现象，因此这些高温工艺不适用于NC-WC/Co涂层。该项目将通过集成两种新工艺来克服这一技术缺陷，一种是称为动态金属化(KM)的固态喷涂工艺，另一种是称为集成机械和热激活(IMTA)的纳米晶粉末工艺。采用低温KM工艺将IMTA法制备的纳米晶WC/Co粉末沉积到高强度钢上。预计这项技术一旦开发出来，将提供金属部件和硬面涂层，与当今传统的粗晶涂层相比，性能将有显著改善。这项技术的更广泛影响可能是改善航空航天和陆基燃气轮机发动机和飞机执行器市场的纳米晶涂层，每年超过10亿美元。所有这些市场的原始设备制造商和军事维修站都在积极寻找替代涂层，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、基础设施和交通运输行业获得许多应用，其中具有更高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.