热障涂层在热载荷下的高温氧化和热烧蚀性能研究

Research on High Temperature Oxidation and Thermal Ablation Performance of Thermal Barrier Coatings under Thermal Load

热障涂层具有良好的隔热性能,保护高温合金基底正常工作,提高部件工作寿命。由于涂层部件服役于高温环境,会产生热烧蚀并发生高温氧化等作用,造成涂层表面裂纹的产生,甚至涂层/基底的界面破坏,缩短部件使用寿命。所以研究热障涂层体系在热载荷下的破坏行为极其重要。通过设计试样在相同温度下不同氧化时间的研究实验。结果表明热生长氧化层成分主要是Al的氧化物,其厚度与氧化时间的关系服从抛物线规律(氧化动力学曲线);对高温氧化后的试样进行纳米压痕实验,发现随着氧化时间的增加,涂层的弹性模量和硬度都会增加并趋于稳定。

Thermal barrier coatings(TBCs) with good excellent thermal insulation property,are widely used in advanced gas turbines to protect the alloy substrate from the high temperature and improve its working life. Because of working in the high temperature, TBCs will bear the thermal fatigue and some other environmental damage. These will result in surface cracks or the interface cracks in the TC/Sub interface. Then the substrate will expose in the high temperature environment and shorten the service life. So investigating the structure of thermal barrier coatings under thermal loads is extremely important. In this paper, we conduct experiments about the coating which suffer the temperature in the different time. We can conclude that the thickness of thermal grown oxidation(TGO), which is mainly the aluminum(Al) oxide, follows the oxidation kinetic curve. Then we conduct a nano-indentation experiment on the samples, and found that the modulus and hardness of the coating will increase and come to stability as time increases.