EAGER/Collaborative Research: Laser Sintering of Nanolayered Carbon Nanotube Paper for Functionally Gradient Ceramic Nanocomposites

这一早期概念探索研究资助项目的研究目标是研究通过一种新的造纸-激光烧结工艺制备的功能梯度纳米层状陶瓷纳米复合涂层的工艺-结构-性能关系，并验证碳纳米管的加入可以显著提高陶瓷涂层的力学性能的假设。这是一个高风险但高回报的项目，因为新工艺与传统的制备陶瓷纳米复合涂层的方法有根本的不同。该项目的方法包括：1)造纸工艺，制备由陶瓷纳米颗粒和碳纳米管组成的纳米级碳纳米管纸；2)逐层激光烧结，制备功能梯度涂层；3)表征所制备的纳米复合涂层的组织结构和力学性能。在造纸-激光烧结过程中，碳纳米管可以在电场作用下悬浮在悬浮液中实现良好的分散和可控的取向。通过对纸张逐层激光烧结，可以实现合适的功能梯度多层涂层，每一层中的组成都是不同的和可控的。所开发的功能梯度涂层可显著降低涂层-基材界面出现裂纹和分层的可能性。具体地说，这项研究将用于证明碳纳米管的加入是否会改善涂层的断裂韧性。这项研究将通过促进陶瓷纳米复合涂层的制造科学和更好地了解其结构-性能关系，对陶瓷纳米复合涂层产生重大影响。该项目将对航空航天、汽车、生物医学和许多其他领域产生广泛的潜在影响，在这些领域，陶瓷涂层发挥着关键作用。一些例子包括燃气轮机发动机的热障涂层，以及许多医疗植入物和机械部件所需的耐磨或耐腐蚀涂层。

The research objective of this EArly-concept Grant for Exploratory Research (EAGER) project is to study the processing-structure-property relationship of functionally gradient nanolayered ceramic nanocomposite coating fabricated through a new paper making - laser sintering process, and test the hypothesis that the addition of carbon nanotubes can yield significant enhancement in mechanical properties of the ceramic coatings. It is a high-risk but high-payoff project because the new process is radically different from traditional approaches to make ceramic nanocomposite coating. This project's approach involves: 1) paper making process to manufacture nanolayered carbon nanotube paper consisting of both ceramic nanoparticles and carbon nanotubes, 2) laser sintering of the paper layer by layer to fabricate the functionally gradient coating, and 3) characterization of microstructures and mechanical properties of the fabricated nanocomposite coating. In the paper making - laser sintering process, good dispersion and controlled alignment of carbon nanotubes will be achieved in a suspension under an electric field. A suitable functionally gradient multilayered coating can be realized by laser sintering of the paper layer by layer, with varied and controlled compositions in each layer. The developed functionally gradient coating can potentially decrease the possibility of cracks and delamination at the coating-substrate interface significantly. Specifically, the grant will be used to demonstrate whether the addition of the carbon nanotubes will result in improved fracture toughness of the coating.This research will have a major impact on ceramic nanocomposite coating through advancing manufacturing science of ceramic nanocomposite coating and better understanding its structure-property relationship. The project will have broad potential impacts on aerospace, automotive, biomedical, and many other areas, where ceramic coatings play a key role. Some examples include the thermal barrier coatings in gas turbine engines, and the wear or corrosion resistance coatings needed in numerous medical implants and mechanical components.