热障涂层导热率的测量及控制技术

摘要

作为一种有效的改善发动机的性能、减少发动机零部件的成本,延长其使用寿命的技术,热障涂层(TBC)已得到了越来越广泛的应用.在所有涉及热障涂层性能的物理参数中,导热率被认为是最重要的指标之一. 本文介绍了热障涂层技术的发展现状,总结了热障涂层导热率测量的3种主要方法(激光发射法、3-ω法和光声法)的优缺点及适用范围,讨论了减少热障涂层导热率的主要技术.从试验数据来看,加入特殊的添加剂、改善涂层的微观组织构、采用多层复合结构是降低若障涂层导热率的有效方法.%As an effective way to lower the cost and to extend the lifetime of engine components as well as to improve the engine performance,thermal barrier coatings have been widely used in modern society.Among all the thermophysical properties of TBC,the thermal conductivity is regarded as the most important property.In this paper,the current status of TBC technology is reviewed, the three main ways to measure the thermal conductivity of TBC which were laser flash diffusivity technique, 3-ω technique and photoacoustic technique are summarized, and the methods to reduce the thermal conductivity are discussed in detail. It is seen that the addition of dopants, the change of the coating microstructure and the layer of the coating are all very powerful ways to reduce the thermal conductivity of TBC.