The YSZ coatings are prepared by the plasma spray-physical vapor deposition(PS-PVD)technology based on a specific experimental design.The structure,thickness and growth angle of YSZ coatings on the entire circumferent...The YSZ coatings are prepared by the plasma spray-physical vapor deposition(PS-PVD)technology based on a specific experimental design.The structure,thickness and growth angle of YSZ coatings on the entire circumferential surface of the cylindrical sample are studied.The results indicated that the structure,thickness and deflection growth angle of YSZ coatings are related to the orientation of deposition location.The numerical simulation of the multiphase mixed fluid near the substrate is carried out and the deposition regularity and mechanism of YSZ coatings prepared by PS-PVD is deduced.The growth rate is related to the local characteristics of the plasma flow field,and is directly proportional to the field pressure and inversely proportional to the field velocity.The growth angle of the coating is generally affected by the flow direction of the plasma jet.Especially,the normal component of velocity vector,V_(norm),mainly affects the speed at which the coating grows vertically upwards.The tangential component of velocity vector,V_(tan),determines the degree that the coating growth direction deviates from the vertical direction.When V_(tan)≠0,the coating forms a fine column with a certain deflection angle and finally develops into an oblique columnar structure.展开更多
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 u...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.展开更多
Plasma spray-physical vapor deposition(PS-PVD)as a novel process was used to prepare feather-like columnar thermal barrier coatings(TBCs).This special microstructure shows good strain tolerance and non-line-of-sight(N...Plasma spray-physical vapor deposition(PS-PVD)as a novel process was used to prepare feather-like columnar thermal barrier coatings(TBCs).This special microstructure shows good strain tolerance and non-line-of-sight(NLOS)deposition,giving great potential application in aero-engine.However,due to serious service environment of aero-engine,particle erosion performance is a weakness for PS-PVD 7YSZ TBCs.As a solution,an Al-modification approach was proposed in this investigation.Through in-situ reaction of Al and ZrO2,anα-Al2O3 overlay can be formed on the surface of 7YSZ columnar coating.The results demonstrate that this approach can improve particle erosion resistance since hardness improvement of Al-modified TBCs.Meanwhile,as another important performance of thermal cycle,it has a better optimization with 350-cycle water-quenching,compared with the as-sprayed TBCs.展开更多
基金the financial support from National Natural Science Foundation of China(51771059)R&D Program in Key Fields of Guangdong Province of China(2019B010936001)+2 种基金National Science and Technology Major Project of China(2017-VI-0010-0081)Science and Technology Project of Guangdong Province of China(2017A070701027,2014B070705007)Sciences Project of Guangdong Academy of China(2019GDASYL-0104022)。
文摘The YSZ coatings are prepared by the plasma spray-physical vapor deposition(PS-PVD)technology based on a specific experimental design.The structure,thickness and growth angle of YSZ coatings on the entire circumferential surface of the cylindrical sample are studied.The results indicated that the structure,thickness and deflection growth angle of YSZ coatings are related to the orientation of deposition location.The numerical simulation of the multiphase mixed fluid near the substrate is carried out and the deposition regularity and mechanism of YSZ coatings prepared by PS-PVD is deduced.The growth rate is related to the local characteristics of the plasma flow field,and is directly proportional to the field pressure and inversely proportional to the field velocity.The growth angle of the coating is generally affected by the flow direction of the plasma jet.Especially,the normal component of velocity vector,V_(norm),mainly affects the speed at which the coating grows vertically upwards.The tangential component of velocity vector,V_(tan),determines the degree that the coating growth direction deviates from the vertical direction.When V_(tan)≠0,the coating forms a fine column with a certain deflection angle and finally develops into an oblique columnar structure.
基金This work was supported by Guangdong Special Support Program(No.2019BT02C629)GDAS0 Project of Science Technology Development(No.2020GDASYL-20200402005)+1 种基金The Scientific Research Fund of Guangdong Province,China(No.2016A030312015)Doctoral Research Initiation Program(No.84KZ-KZ08072).
文摘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We would like to acknowledge the financial support from the National Natural Science Foundation of China(52172067)Guangdong Province Outstanding Youth Foundation(2021B1515020038)+1 种基金Guangdong Special Support Program(2019BT02C629)Guangdong Academy of Sciences Program(2020GDASYL-20200104030).
文摘Plasma spray-physical vapor deposition(PS-PVD)as a novel process was used to prepare feather-like columnar thermal barrier coatings(TBCs).This special microstructure shows good strain tolerance and non-line-of-sight(NLOS)deposition,giving great potential application in aero-engine.However,due to serious service environment of aero-engine,particle erosion performance is a weakness for PS-PVD 7YSZ TBCs.As a solution,an Al-modification approach was proposed in this investigation.Through in-situ reaction of Al and ZrO2,anα-Al2O3 overlay can be formed on the surface of 7YSZ columnar coating.The results demonstrate that this approach can improve particle erosion resistance since hardness improvement of Al-modified TBCs.Meanwhile,as another important performance of thermal cycle,it has a better optimization with 350-cycle water-quenching,compared with the as-sprayed TBCs.
