NiCoCrAlYTa coatings have been deposited onto an aircraft gas turbine engine blade using a LPPS unit equipped with a computerized robot. Optimal processing conditions, including spray parameters, the trajectory of the...NiCoCrAlYTa coatings have been deposited onto an aircraft gas turbine engine blade using a LPPS unit equipped with a computerized robot. Optimal processing conditions, including spray parameters, the trajectory of the robot, and the synchronized movements between the torch and the blade, have been developed for superior coating properties. Transferred arc treatment, providing a preheating and a cleaning of the substrate surface, enhances the adherence of the coatings to the substrate. The resulting LPPS coatings show dense and uniform characteristics with ideal hardness, and good corrosion resistance to cycle oxidation.展开更多
The interfaces of two materials, Ni/Fe and Cu/Ni, deposited by low pressure plasma spraying method, were studied by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) combined with ...The interfaces of two materials, Ni/Fe and Cu/Ni, deposited by low pressure plasma spraying method, were studied by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) combined with energy dispersive X ray spectroscopy (EDS). The adhesion between coatings and substrates was measured with the aid of Knoop interfacial indentation testing method. The results show that the interfacial microstructures have strong influence on the mechanical properties. Cu/Ni interface is weak link with NiO amorphous phase. Ni/Fe interfacial layer consists primarily of Fe and Ni oxide crystalline phases, containing dispersive (Fe, Ni) spotlike intermetallic compound phase in nanometer dimension, and the interfacial interdiffusion was detected. The micro mechanism of interfacial fracture was discussed.展开更多
Yttria-stabilized zirconia（ YSZ） coatings were deposited by low pressure plasma spray（ LPPS） in 1.0× 10^4 Pa,1.5 × 10^4 Pa,and 2.5 × 10^4 Pa. Both in-flight particle diagnostic detected by DPV-2000 ...Yttria-stabilized zirconia（ YSZ） coatings were deposited by low pressure plasma spray（ LPPS） in 1.0× 10^4 Pa,1.5 × 10^4 Pa,and 2.5 × 10^4 Pa. Both in-flight particle diagnostic detected by DPV-2000 system and ANSYS-FLUENT software were used to study the connection between the parameters of flying particles and the coating formation,which might help to recognize the relationship between the operation parameters and the coatings quality. The results of simulation showed that particles in a lower spray pressure could achieve a higher velocity. The particle velocity was around 380 m/s at a distance of 35 cm from the nozzle at 1.0 × 10^4 Pa while only 300 m/s at 2.5 × 10^4 Pa in actual measurement.The results showed that the velocity of particles increased with decreasing the spray pressure,which might enhance the flattening rate of coatings and thereby decreased the porosity. The deposited YSZ coating with the lowest porosity can be gained under 1.0 × 10^4 Pa condition.展开更多
文摘NiCoCrAlYTa coatings have been deposited onto an aircraft gas turbine engine blade using a LPPS unit equipped with a computerized robot. Optimal processing conditions, including spray parameters, the trajectory of the robot, and the synchronized movements between the torch and the blade, have been developed for superior coating properties. Transferred arc treatment, providing a preheating and a cleaning of the substrate surface, enhances the adherence of the coatings to the substrate. The resulting LPPS coatings show dense and uniform characteristics with ideal hardness, and good corrosion resistance to cycle oxidation.
文摘The interfaces of two materials, Ni/Fe and Cu/Ni, deposited by low pressure plasma spraying method, were studied by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) combined with energy dispersive X ray spectroscopy (EDS). The adhesion between coatings and substrates was measured with the aid of Knoop interfacial indentation testing method. The results show that the interfacial microstructures have strong influence on the mechanical properties. Cu/Ni interface is weak link with NiO amorphous phase. Ni/Fe interfacial layer consists primarily of Fe and Ni oxide crystalline phases, containing dispersive (Fe, Ni) spotlike intermetallic compound phase in nanometer dimension, and the interfacial interdiffusion was detected. The micro mechanism of interfacial fracture was discussed.
基金financially supported by the National Natural Science Foundation of China(No.51301112, No.51401129)Natural Science Foundation of Liaoning Province of China(No.201602553 )+1 种基金China Postdoctoral Science Foundation(2015M571327)The Science Research Program of Education Department in Liaoning Province(No.L2014048)
文摘Yttria-stabilized zirconia（ YSZ） coatings were deposited by low pressure plasma spray（ LPPS） in 1.0× 10^4 Pa,1.5 × 10^4 Pa,and 2.5 × 10^4 Pa. Both in-flight particle diagnostic detected by DPV-2000 system and ANSYS-FLUENT software were used to study the connection between the parameters of flying particles and the coating formation,which might help to recognize the relationship between the operation parameters and the coatings quality. The results of simulation showed that particles in a lower spray pressure could achieve a higher velocity. The particle velocity was around 380 m/s at a distance of 35 cm from the nozzle at 1.0 × 10^4 Pa while only 300 m/s at 2.5 × 10^4 Pa in actual measurement.The results showed that the velocity of particles increased with decreasing the spray pressure,which might enhance the flattening rate of coatings and thereby decreased the porosity. The deposited YSZ coating with the lowest porosity can be gained under 1.0 × 10^4 Pa condition.
