Li Zhuoyue, Wang Cheng, Ding Xiangyu, Li Xin, Yu Jiabo, Li Qiuliang, Qu Yi
Fundamental Department, Air Force Engineering University, Xi'an 710051, China.
College of Aircraft Engineering, Nanchang Hangkong University, Nanchang 330063, China.
Materials (Basel). 2022 Sep 29;15(19):6758. doi: 10.3390/ma15196758.
Diffusion aluminum coating is crucial to protect aero-engine turbine blades from high-temperature oxidation. Slurry aluminizing, as a commonly-used coating preparation technology, has variations in the process parameters that directly affect the quality of the coating. Therefore, this paper investigates the effect of slurry thickness on coating quality. Different forms of aluminized coatings were obtained by coating nine DZ22B nickel-based superalloy plates of the same size with different slurry thicknesses while keeping other parameters constant. These aluminized coatings were characterized using a scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), an X-ray diffractometer (XRD), and a surface gauge. The results show that the AlNi phase dominates the matrix of the aluminized coating, and the outer layer of the coating has white dotted precipitates of Cr. As the slurry thickness increases, the coating thickness increases, and the proportion of the outer layer in the overall coating increases. In contrast, the thickness of the interdiffusion layer does not change significantly. The thicker the slurry, the higher the Al content of the coating surface. A medium-thickness slurry can form a smooth aluminizing coating with a roughness Ra < 4.5 μm surface. The combined results show that a medium-thick slurry can produce a high-quality coating.
扩散渗铝涂层对于保护航空发动机涡轮叶片免受高温氧化至关重要。作为一种常用的涂层制备技术，浆料渗铝在工艺参数上存在差异，这些差异直接影响涂层质量。因此，本文研究了浆料厚度对涂层质量的影响。通过在九块相同尺寸的DZ22B镍基高温合金板上涂覆不同厚度的浆料，同时保持其他参数不变，获得了不同形式的渗铝涂层。使用配备能谱仪（EDS）的扫描电子显微镜（SEM）、X射线衍射仪（XRD）和表面测量仪对这些渗铝涂层进行了表征。结果表明，AlNi相在渗铝涂层的基体中占主导地位，涂层外层有Cr的白色点状析出物。随着浆料厚度增加，涂层厚度增加，且外层在整个涂层中的比例增加。相比之下，互扩散层的厚度变化不明显。浆料越厚，涂层表面的Al含量越高。中等厚度的浆料可以形成表面粗糙度Ra < 4.5 μm的光滑渗铝涂层。综合结果表明，中等厚度的浆料可以制备出高质量的涂层。
