DMREF/Collaborative Research: Nitride Discovery - Creating the Knowledge Base for Hard Coating Synthesis

在运动部件必须防止过度磨损的应用中，通常会在部件上涂上硬质涂层。被称为氮化物的一类硬质陶瓷材料通常用于这些涂层，但氮化物涂层的性能有限，而且往往不足，导致重要部件的击穿。据预测，新型氮化物材料的耐磨性和耐腐蚀性有望得到显著改善。然而，这些材料的制造仍然是一个挑战。该奖项支持系统地确定能够制造这些所需的新氮化物材料的条件的研究。这项研究的结果将通过有针对性的合成方法加速发现坚硬、耐磨和耐腐蚀的涂层，产生用于新兴应用的新涂层材料，包括燃油效率高的喷气发动机和燃气轮机、环保的无润滑剂刀具、高温聚光太阳能发电厂和风力涡轮机。这项工作中的涂层设计方法有助于引入有前途的新氮化物，因为同时优化成分、微观结构和沉积过程的传统方法成本太高，速度太慢。该方法通过一条确定的途径，从热力学和动力学参数确定工艺参数空间，以获得所需的成分和微观结构，然后通过实验合成涂层。该方法基于实验和密度泛函理论计算的迭代结合，以确定过渡金属氮化物涂层沉积过程中的氮掺入动力学和相形成。研究工作主要集中在涂层合成过程中反应和扩散速率的系统确定以及过渡金属氮化物层生长表面的局部平衡。将开发一个定量模型，使用测量和计算的值来预测沉积氮化物的成分和相作为入射离子能量以及生长温度和压力的函数。该模型将通过实验涂层沉积得到验证。将探索沉积新的超硬、韧性和空位稳定的氮化物相。这项研究收集的数据将通过一个开放的在线数据库公开提供。

In applications where moving parts must be protected from excessive wear, hard coatings are often applied to components. The class of hard ceramic materials known as nitrides are often used for these coatings, but the performance of nitride coatings is limited and often insufficient, leading to breakdown of important components. New nitride materials have been predicted that are expected to have the significantly improved properties for wear resistance and corrosion resistance. Fabrication of these materials, however, remains a challenge. This award supports research to systematically determine the conditions that will enable the manufacture of these desired new nitride materials. The results of this research will accelerate discovery of hard, wear-resistant and corrosion-resistant coatings through a targeted synthesis approach, yielding new coating materials for emerging applications including fuel-efficient jet engines and gas turbines, environmentally-friendly lubricant-free cutting tools, high-temperature concentrating solar power plants, and wind turbines.The coatings-by-design approach in this work facilitates the introduction of promising new nitrides, which have remained unexplored because the traditional approach of simultaneously optimizing composition, microstructure, and deposition process is too costly and slow. This method enables a deterministic pathway to ascertain the processing parameter space to achieve the desired composition and microstructure from thermodynamic and kinetic parameters, and then synthesize the coating experimentally. This method is based on an iterative combination of experiments and density functional theory calculations, to determine nitrogen incorporation kinetics and phase formation during deposition of transition metal nitride coatings. The research effort focuses primarily on the systematic determination of reaction and diffusion rates and local equilibria at the surface of growing transition metal nitride layers during coating synthesis. A quantitative model will be developed that predicts composition and phase of deposited nitrides as a function of incident ion energetics and growth temperature and pressure, using both measured and calculated values. The model will be verified by experimental coating deposition. Deposition of new super-hard, tough, and vacancy-stabilized nitride phases will be explored. Data collected in this research will be made publicly available through an open online database.