摘要
Ru-doped NiAlHf coatings were deposited on Ni-based single crystal substrate by arc ion plating technology.The failure mechanism and interfacial diffusion behavior were comparatively investigated with NiAlHf coating using scanning electron microscopy,electron probe micro-analyzer,and transmission electron microscopy.The results indicated that microstructure evolution of oxide scale induced by element diffusion process significantly affected oxidation resistance of NiAlHf/Ru coatings,resulting in formation of cracks and voids,thereby accelerating failure process.The precipitates in interdiffusion zone and secondary reaction zone of the substrate initiated by interfacial element diffusion were P phase andσphase,respectively.And the discrepancy in content was elucidated from the perspective of thermodynamics and kinetics.Besides,microstructural evolution between NiAlHf/Ru coatings and substrate was also deliberated.The research could not only provide profound understanding of NiAlHf/Ru coatings failure mechanism,but also had significant guidance for suppressing precipitation of topological close-packed phases and facilitating development of single crystal Ni-based superalloys.
基金
This work was supported by Guangdong Special Support Program(No.2019BT02C629)
GDAS0 Project of Science Technology Development(No.2020GDASYL-20200402005)
The Scientific Research Fund of Guangdong Province,China(No.2016A030312015)
Doctoral Research Initiation Program(No.84KZ-KZ08072).
