基于晶粒尺寸效应的金属基热障涂层隔热机制与热稳定性研究

项目名称： 基于晶粒尺寸效应的金属基热障涂层隔热机制与热稳定性研究

项目编号： No.51301009

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 周正

作者单位： 北京工业大学

项目金额： 25万元

中文摘要： 低散热发动机技术是降低汽车尾气污染物排放、提高能源利用率的有效途径和必然发展趋势，但是其关键技术之一，即热端面热障涂层材料的服役稳定性，是目前制约其大范围推广应用的技术瓶颈。针对陶瓷基热障涂层难以解决的热疲劳等问题，提出金属基热障涂层的设计理念是较为新颖的研究思路，但对于其隔热机制和热稳定性等基础科学问题，还缺乏足够的认识。基于此，本项目围绕晶粒尺寸对材料热导率的影响这一基本思路，在合金体系选择设计的基础上，通过涂层热导率影响因素解耦的分析方法，首先对块体非晶/纳米晶材料的隔热机制、及晶粒尺寸的影响规律进行系统研究，进而在电子、声子和结构缺陷等微观本质上，揭示出金属基热障涂层的隔热机制。进一步开展涂层长周期热稳定性研究，阐明涂层组织结构随温度和时间的演化规律及隔热性能的退化程度。相关成果为非晶/纳米晶材料应用领域的开拓、及金属基热障涂层的实际设计与工程应用，提供重要的理论基础和科学依据。

中文关键词： 金属基热障涂层；晶粒尺寸；热导率；热稳定性；微观组织结构

英文摘要： Low Heat Rejection (LHR) engines are considered to be a trend of development, and an effective approach to reduce exhaust emissions and improve fuel economy of vehicles. However, the service lifetime and stability of thermal barrier coatings (TBCs), which is regarded as one of the key technologies, have significantly restricted the extended application of LHR engines. The concept of metal-based thermal barrier coatings (MBTBCs) initiates a novel idea to overcome the problems in which ceramic-based thermal barrier coatings (CBTBCs) can not solve, such as thermal fatigue. Nevertheless, it is still lack of sufficient understanding on the insulation mechanism and thermal stability of MBTBCs up to now. Therefore, in this work, related investigations will be conducted based on the fundamental of grain size effect on material thermal conductivity. The selection and optimization of metallic alloy components should be processed firstly to satisfy the demands of coatings microstructure and properties, in terms of high glass forming ability and crystallization temperature. To clarify the insulation mechanism of MBTBCs, uncoupled analysis method will be used to study the separate contribution to coating thermal conductivity of impact factors, respectively. Consequently, the insulation mechanism of MBTBCs could be characteri

英文关键词： Metal-based thermal barrier coating；grain size；thermal conductivity；thermal stability；microstructure