The Design and Analysis of Aluminide Surface Layers for Low Temperature Synthesis

低温合成铝化物表面层的设计与分析

• 批准号: 0926796
• 负责人: John Perepezko
• 金额: $ 31万
• 依托单位: University of Wisconsin-Madison
• 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: 2009-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0926796&HistoricalAwards=false
• 关键词: Design; Analysis; Aluminide; Surface; Layers

The focus of the research is to develop an understanding of an innovative low temperature synthesis pathway for oxidation resistant aluminide coatings without degradation of alloy steel properties that occurs with high temperature processing. The mechanism that enables the development of a large Al flux at low temperature must be resolved to provide the fundamental understanding that will allow for a robust process control. The Al5Fe2 phase appears to be an important component of the reaction pathway and is characterized by a high lattice defect content. A quantitative coating growth kinetics analysis will be conducted to confirm the role of the Al5Fe2 phase in enhancing low temperature synthesis. An examination of the stability of the Al5Fe2 phase will allow for an understanding of the defect structure and diffusion kinetics. While the rapid kinetics is an advantage in initial coating synthesis, it is a concern during service since it results in depletion of Al and the loss of oxidation protection. In order to address the lifetime extension the multicomponent diffusion pathways will be assessed so that a novel kinetic biasing strategy can be employed to develop in-situ diffusion barriers and compliant layers as part of an integrated coating design.The advancement in the understanding and control of low temperature aluminide coating synthesis reactions resulting from the research will yield a deeper fundamental knowledge of the governing kinetic mechanisms. The introduction of a novel kinetic biasing strategy in order to develop an in-situ diffusion barrier will provide a key missing component that is required in order to implement low temperature synthesis as an effective means to protect alloy steels in energy conversion applications to allow for increased power generation and efficiency. The coating design strategies developed in this research have a general application as a cost effective means to enhancing the resistance of structural materials to degradation under aggressive environments at high temperature. An important component of the project effort will be the education of a graduate student. Further, lecture demonstrations on coating synthesis will be incorporated into outreach programs for high school and incoming undergraduate students.

这项研究的重点是建立对抗氧化抗氧化铝涂层的创新低温合成途径的理解，而不会在高温加工时降解合金钢性能。必须解决在低温下开发大型AL通量的机制，以提供基本的理解，从而可以进行强大的过程控制。 AL5FE2相似乎是反应途径的重要组成部分，其特征是高晶格缺陷含量。 将进行定量涂料生长动力学分析，以确认AL5FE2相在增强低温合成中的作用。对AL5FE2阶段的稳定性的检查将允许了解缺陷结构和扩散动力学。虽然快速动力学是初始涂层合成的优势，但在服务过程中是一个问题，因为它导致Al耗尽和氧化保护丢失。 为了解决寿命延长，将评估多组分扩散途径，以便可以采用一种新型的动力学偏见策略来发展原位的扩散屏障和兼容层，作为集成涂料设计的一部分。对低温铝涂层的理解和控制，可以从研究中获得对低温铝涂层的理解和控制，从而使研究范围具有深度的基本化。引入了一种新型的动力学偏见策略，以开发原位的扩散屏障将提供一个关键的缺失组件，以实施低温合成作为在能量转换应用中保护合金钢的有效手段，以提高发电和效率。这项研究中开发的涂料设计策略具有一般应用，是一种具有成本效益的手段，可以增强在高温下在侵略性环境下降解的结构材料的抵抗力。项目工作的重要组成部分是对研究生的教育。此外，有关涂料合成的演示演示将纳入高中和入学的本科生的外展计划中。