Development of Thermal Barrier Coating System with an intermediate layer containing MoSi2 with Superior Thermal Cyclic Properties

针对燃气轮机部件上的热障涂层系统，提出了提高其耐热循环性能的方法。传统的热障涂层由双层涂层、面层涂层和粘结涂层组成。该系统具有MoSi2中间保护层，以防止粘结涂层的氧化，常规双层等离子喷涂涂层在20次热循环后剥离。另一方面，所开发的三层涂层体系在60次循环后都不会分层。所开发的三层涂层体系的耐热循环性能提高的原因是存在于顶层和粘结层之间的MoSi2层具有自修复性能。MoSi2氧化形成二氧化硅，它封闭了在顶层涂层和粘结层之间形成的裂纹和气孔。

The authors have developed the method of improving the thermal cyclic resistance for the thermal barrier coating system that is deposited on gas turbine components. Conventional thermal barrier coating consists of duplex system, top coating and bond coating. The developed system has a protective intermediate layer of MoSi2 for preventing oxidation of the bond coating, Conventional duplex plasma sprayed coating was delaminated after 20 thermal cycles. On the other hand, the developed triple layered coating system was not delaminated up to 60 cycles. The reason of the enhanced resistance to thermal cycles for the developed triple layered coating system is that the MoSi2 layer existing between the top coating and the bond coating has the self-repairing property. MoSi2 oxidizes to form SiO2 which seals the cracks and pores formed between the top coating and the bond coating.