The functionally graded thermal barrier coatings （FG-TBCs） with 80%ZrO2-13%CeO2-7%Y2O3 （C-YSZ）/NiCoCrAlY were prepared using a recently developed supersonic plasma spraying（S-PS） with dual powder feed ports syst...The functionally graded thermal barrier coatings （FG-TBCs） with 80%ZrO2-13%CeO2-7%Y2O3 （C-YSZ）/NiCoCrAlY were prepared using a recently developed supersonic plasma spraying（S-PS） with dual powder feed ports system. The thermal shock experiment of FG-TBCs specimens was carried out by means of the automatic thermal cycle device, in which the samples were heated to 1200℃ by oxygen-acetylene flame jet then water-quenched to ambient temperature. The temperature—time curves of specimens and photographs can be watched on-line and recorded by a computer during the test. The results show that the totally 1mm-thick FG-TBCs have excellent thermal shock resistance due to the fact that the coatings have no any peeling-off after 200 thermal cycles. The microstructures and morphologies of FG-TBCs were characterized and analyzed by SEM.展开更多
The thermal barrier coatings with NiCrAlY alloy bonding layer, NiCrAlY Y 2O 3 stabilized ZrO 2 transition layer and Y 2O 3 stabilized ZrO 2 ceramic layer are prepared on nickel alloy substrates using the plasma spray ...The thermal barrier coatings with NiCrAlY alloy bonding layer, NiCrAlY Y 2O 3 stabilized ZrO 2 transition layer and Y 2O 3 stabilized ZrO 2 ceramic layer are prepared on nickel alloy substrates using the plasma spray technique. The relationship among the composition, structure and property of the coatings are investiga ted by means of optical microscope, scanning electronic microscope and the experiments of thermal shock resistance cycling and high temperature oxidation resistance. The results show that the structure design of introdu cing a transition layer between Ni alloy substrate and ZrO 2 ceramic coating guarantees the high quality and properties of the coatings; ZrO 2 coatings doped with a little SiO 2 possesses better thermal shock resistance and more excellent hot corrosion resistance as compared with ZrO 2 coating materials without SiO 2 ;the improvement in performance of ZrO 2 coating doped with SiO 2 is due to forming more dense coating structure by self closing effects of the flaws and pores in the ZrO 2 coatings.展开更多
The Fe-based coatings in powder form were deposited on a steel type E335 by flame spraying technique.The effects of the post heat treatment on the microstructure and the mechanical properties of sprayed coatings were ...The Fe-based coatings in powder form were deposited on a steel type E335 by flame spraying technique.The effects of the post heat treatment on the microstructure and the mechanical properties of sprayed coatings were studied.Post heat treatment was conducted in a furnace in air at 623 K,823 K and 1023 K for 1 h and then cooled in air.The results showed that with the increase of annealing temperature,the microstructure of coating treated at 823 K and 1023 K had several changes as follows:the reduction of porosity,formation of carbides and oxides.It was found that the solid solution FCC(Fe,Ni),intermetallic compound AlFe3 and carbides[Fe,C]were the main phases for coatings as-sprayed and treated at 623 K and while iron carbide,molybdenum carbide and oxide as Fe3O4 became the main phases and reinforced the solid solution FCC(Fe,Ni)phase for annealed coatings at 823 K.However,it was observed the disappearance of molybdenum carbide and oxide Fe3O4 at 1023 K.The coating annealed at 823 K exhibited an excellent wear resistance than the as-sprayed and annealed coatings at 623 K and 1023 K and shows the lower wear rate than another coating treated or as sprayed.展开更多
文摘The functionally graded thermal barrier coatings （FG-TBCs） with 80%ZrO2-13%CeO2-7%Y2O3 （C-YSZ）/NiCoCrAlY were prepared using a recently developed supersonic plasma spraying（S-PS） with dual powder feed ports system. The thermal shock experiment of FG-TBCs specimens was carried out by means of the automatic thermal cycle device, in which the samples were heated to 1200℃ by oxygen-acetylene flame jet then water-quenched to ambient temperature. The temperature—time curves of specimens and photographs can be watched on-line and recorded by a computer during the test. The results show that the totally 1mm-thick FG-TBCs have excellent thermal shock resistance due to the fact that the coatings have no any peeling-off after 200 thermal cycles. The microstructures and morphologies of FG-TBCs were characterized and analyzed by SEM.
文摘The thermal barrier coatings with NiCrAlY alloy bonding layer, NiCrAlY Y 2O 3 stabilized ZrO 2 transition layer and Y 2O 3 stabilized ZrO 2 ceramic layer are prepared on nickel alloy substrates using the plasma spray technique. The relationship among the composition, structure and property of the coatings are investiga ted by means of optical microscope, scanning electronic microscope and the experiments of thermal shock resistance cycling and high temperature oxidation resistance. The results show that the structure design of introdu cing a transition layer between Ni alloy substrate and ZrO 2 ceramic coating guarantees the high quality and properties of the coatings; ZrO 2 coatings doped with a little SiO 2 possesses better thermal shock resistance and more excellent hot corrosion resistance as compared with ZrO 2 coating materials without SiO 2 ;the improvement in performance of ZrO 2 coating doped with SiO 2 is due to forming more dense coating structure by self closing effects of the flaws and pores in the ZrO 2 coatings.
文摘The Fe-based coatings in powder form were deposited on a steel type E335 by flame spraying technique.The effects of the post heat treatment on the microstructure and the mechanical properties of sprayed coatings were studied.Post heat treatment was conducted in a furnace in air at 623 K,823 K and 1023 K for 1 h and then cooled in air.The results showed that with the increase of annealing temperature,the microstructure of coating treated at 823 K and 1023 K had several changes as follows:the reduction of porosity,formation of carbides and oxides.It was found that the solid solution FCC(Fe,Ni),intermetallic compound AlFe3 and carbides[Fe,C]were the main phases for coatings as-sprayed and treated at 623 K and while iron carbide,molybdenum carbide and oxide as Fe3O4 became the main phases and reinforced the solid solution FCC(Fe,Ni)phase for annealed coatings at 823 K.However,it was observed the disappearance of molybdenum carbide and oxide Fe3O4 at 1023 K.The coating annealed at 823 K exhibited an excellent wear resistance than the as-sprayed and annealed coatings at 623 K and 1023 K and shows the lower wear rate than another coating treated or as sprayed.
