镍基高温合金铝硅涂层高速旋转燃气热冲击实验研究

Experimental Study on the Thermal Shock of Nickel-Based Superalloy with Al-Si Coating Using High-Speed Rotating Gas

摘要:

为了提高叶片在恶劣服役环境下的使用性能，用料浆法在DZ417G高温合金表面制备了铝硅涂层，利用涡轮叶片模拟服役环境装置，分别开展了900和1 100 ℃下的高速旋转燃气热冲击实验，并且用扫描电镜对试样表面和截面进行了形貌观察及成分分析，以及采用XRD分析了涂层的相结构。结果表明：经高速旋转热冲击后，涂层结构保持完整，其对基底有良好的保护作用；热冲击后在涂层外表面形成不连续氧化膜，与静态氧化时呈现的氧化机理不同。

Abstract:

To improve the service performance of blades in harsh service environments， Al-Si coatings were prepared on the surface of DZ417G superalloy by the slurry process. The high-speed rotating gas thermal shock experiments were carried out at 900 ℃ and 1 100 ℃ by using the equipment simulating the service environment of turbine blades. The surface and cross-sectional microstructures of the coating were observed and analyzed by scanning electron microscopy. The phase structure of the coating was analyzed by XRD. The results indicate that the Al-Si coating structure remained intact after thermal shock and provided good protection to the superalloy substrate. The oxidation mechanism of the discontinuous oxide film formed on the outer surface of the coating after thermal shock is different from static oxidation.