稀土氧化物改性氧化锆/铂铝热障涂层的制备及其高温性能

Preparation and High Temperature Performance of Rare Earth Oxide Modified Zirconia/PtAl Thermal Barrier Coatings

针对我国某型航空发动机涡轮叶片用DZ125与DZ406高温合金,开展了稀土氧化物改性氧化锆/铂铝热障涂层体系的制备工艺及涂层高温性能研究。采用电镀Pt和气相渗铝的工艺制备了PtAl金属粘结层,研究了镀Pt前处理、不同镀Pt层厚度以及渗铝温度等关键工艺参数对涂层的微观结构和抗高温氧化性能的影响规律。采用优化后的涂层工艺制备的PtAl粘结层在1150℃时的抗氧化性能优异。采用电子束物理气相沉积(EB–PVD)在PtAl粘结层表面制备了稀土氧化物改性的氧化锆(GYb–YSZ)陶瓷涂层。由GYb–YSZ和PtAl组成的热障涂层在1050℃热循环4320次(1050℃保温时间720 h)后,涂层表面状态完好,未发现明显剥落现象,表明该热障涂层体系具备良好的热循环性能。

Aiming at the DZ125 and DZ406 superalloys used in aero-engine turbine blades,a thermal barrier coating system(TBCs)consisting of the rare earth oxide modified zirconia topcoat and platinum modified aluminide(PtAl)bondcoat was applied,and the preparation process and high temperature performance were studied.The PtAl bondcoat was prepared by electroplating platimum followed by vapor aluminizing treatment.Effects of key process parameters such as plating pretreatment,thicknesses of Pt,and aluminizing temperature on the microstructure and high-temperature oxidation resistance of the PtAl coating were studied.The results shows that the PtAl bonadcoat prepared by optimized process has excellent oxidation resistance at 1150℃.On the surface of the PtAl bondcoat,rare earth oxide modified zirconia(GYb–YSZ)ceramic topcoat were prepared by electron beam physical vapor deposition(EB–PVD).The thermal cycling lifetime of the GYb–YSZ/PtAl TBCs at 1050℃is beyond 720 h(4320 times thermal cycling),indicating that the GYb–YSZ/PtAl TBCs have good performance.