GOALI: Ultra-Low Wear Plasma Enhanced Atomic Layer Deposited Nitride Thin Films: Exploring Processing, Structure, Properties and Mechanisms

材料的摩擦和磨损在材料、设备和结构的性能和寿命方面造成了巨大的损失，给美国制造业、能源和基础设施部门带来了相当大的损失。因此，减轻摩擦和磨损的方法对美国经济有利。这一学术联系机会奖(GOALI)支持科学研究，以了解金属氮化物涂层中的摩擦和磨损机理。初步研究表明，金属氮化物涂层是迄今发现的最耐磨的材料之一，有望显著减少磨损对经济和环境的影响。在本研究项目中，合成了金属氮化物薄层，并对其摩擦磨损性能进行了研究。这项工作的目的是确定薄膜的形成(加工)方式与其磨损行为(特性)之间的关系。了解这些关系有助于加强对机械行为的控制，并可获得用于涂层的高性能耐磨材料。开发的新材料对于提高机械系统的效率和寿命具有广泛的重要性，无论是在大范围还是小范围。这项工作是与工业合作伙伴Veeco CNT合作完成的。该行业团队全面参与了这些研究，为参与研究的学生提供了教育机会，并为高性能耐磨涂层材料的商业化提供了一条途径。这项研究考察了用等离子体增强原子层沉积方法沉积的一类过渡金属氮化物的工艺、微观结构和力学行为之间的基本关系。该沉积技术中的高度合成可调谐性允许对薄膜成分和微结构进行裁剪。具体地说，研究了成分对磨损机制的基本作用，以确定固溶体强化与在含钒和钛的膜中形成润滑磨损膜的作用。微晶尺寸对力学性能的影响是通过使用四个控制微晶尺寸的独立合成参数来确定的。研究了氮化物薄膜之间的附着力和界面化学，并与宏观力学行为有关，如分层，这与应用相关。综上所述，这些研究揭示了这种极具前景的材料的基本磨损机理，可以直接与合成和加工参数相关。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Friction and wear of materials accounts for enormous losses in performance and lifetime of materials, devices and structures, at considerable cost to the US manufacturing, energy, and infrastructure sectors. Approaches to mitigate friction and wear are thus beneficial to the US economy. This Grant Opportunities for Academic Liaison with Industry (GOALI) award supports scientific research to understand mechanisms of friction and wear in metal nitride coatings. Preliminary studies revealed metal nitride coatings are among the most wear-resistant materials ever discovered, showing promise for significantly reducing the financial and environmental impacts of wear. In this research project, thin layers of metal nitride compounds are synthesized and their friction and wear properties are investigated. The aim of this work is to identify the relationships between how the films were created (processing) and their wear behavior (properties). Understanding these relationships allows for enhanced control of the mechanical behavior, and can lead to high-performance wear-resistant materials for coatings. The new materials developed are of broad importance for increasing efficiency and lifetime of mechanical systems, on both large and small scales. The work is performed in collaboration with an industrial partner, Veeco CNT. The industry team is integrally involved in the studies, which provides both educational opportunities for students involved in the research and a path to commercialization for high-performance wear-resistant coating materials. This research examines the fundamental relationships among processing, microstructure, and mechanical behavior in a class of transition metal nitrides deposited using plasma-enhanced atomic layer deposition. The high degree of synthetic tunability in this deposition technique allows for tailoring of the film composition and microstructure. Specifically, the fundamental role of composition on wear mechanism is investigated to determine the role of solid solution strengthening versus the formation of a lubricious wear-generated film in films with both vanadium and titanium cations. The impact of crystallite size on mechanical properties is determined for crystallite sizes in the 1-30 nm range using four independent synthesis parameters that control crystallite size. Adhesion and interface chemistry between the nitride films is investigated and related to macroscopic mechanical behavior, such as delamination, that is relevant to applications. Taken together, these studies reveal fundamental wear mechanisms of this highly promising material that can be related directly to the synthesis and processing parameters.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.