GOALI: Understanding the Microstructural Evolution and High-Temperature Behavior of Osmium-Ruthenium Coatings for Dispenser Cathodes

目标：了解分配器阴极锇钌涂层的微观结构演变和高温行为

• 批准号: 0928845
• 负责人: Thomas Balk
• 金额: $ 29.99万
• 依托单位: University of Kentucky Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0928845&HistoricalAwards=false
• 关键词: GOALI; Understanding; Microstructural; Evolution; Temperature

The research objective of this award is an improved understanding of osmium-ruthenium coatings during their fabrication and service in dispenser cathodes. These cathodes, which serve as electron sources in devices such as traveling wave tubes and cathode ray tubes, must withstand demanding environmental conditions including vacuum, high operational temperature and high current density. The osmium-ruthenium films undergo significant microstructural changes during processing and initial service, but must remain intact to maintain electron emission from the cathode. Topics of fundamental scientific importance include the effects of thin film microstructure on the diffusion of refractory metals, as well as the effects of film texture on electron work function. There are also several industrially relevant issues, including how to achieve enhanced emission, longer lifetime and/or lower operating temperature. By systematically investigating the effects of microstructure on the compositional stability and emission properties of annealed and conditioned cathodes, a scientific, microstructure-based understanding of osmium-ruthenium film coatings will be built.The knowledge gained from this project will help advance the dispenser cathode industry from an empirical field with decades of experience, to a field with scientific understanding and the ability to tailor new coatings for improved performance. This project will establish the knowledge needed for a fundamental shift in cathode manufacturing and also mitigate the effects of increasing material costs. If successfully implemented, the results of this research will lead to improved devices for the dispenser cathode industry. This will enable lowered production costs and improved yield, and will benefit customers by increasing cathode lifetime and reliability. The project will enhance both graduate and undergraduate education by providing research experience that has a direct and tangible impact on industry and by providing industrially relevant materials problems for the capstone design course taught by the PI.

该奖项的研究目标是提高对锇钌涂层在制造和使用过程中的理解。这些阴极在行波管和阴极射线管等设备中用作电子源，必须承受苛刻的环境条件，包括真空、高工作温度和高电流密度。锇-钌膜在加工和初始使用期间经历显著的微观结构变化，但必须保持完整以维持阴极的电子发射。具有重要科学意义的课题包括薄膜微观结构对难熔金属扩散的影响，以及薄膜结构对电子功函数的影响。还存在若干工业相关问题，包括如何实现增强的排放、更长的寿命和/或更低的操作温度。通过系统地研究微观结构对退火和调节阴极的成分稳定性和发射性能的影响，将建立对锇-钌膜涂层的科学的、基于微观结构的理解。从该项目中获得的知识将有助于推动分配式阴极行业从具有数十年经验的经验领域，到一个领域的科学理解和能力，以适应新的涂料，以提高性能。该项目将建立阴极制造根本转变所需的知识，并减轻材料成本增加的影响。如果成功实施，这项研究的结果将导致改进的设备，为分配器阴极行业。这将能够降低生产成本和提高产量，并通过增加阴极寿命和可靠性使客户受益。该项目将通过提供对工业有直接和切实影响的研究经验，并为PI教授的顶点设计课程提供工业相关的材料问题，来加强研究生和本科生教育。