Preparation and High Temperature Protection Performance of NiCoCrAlYTa Coating by Arc Ion Plating

In order to improve the service performance of superalloy,NiCoCrAlYTa coatings were deposited on DZ22B superalloy by cathode arc ion plating.Scanning electron microscopy was used to observe the surface and section morphology of the coatings,X-ray diffraction was used to analyze the phase composition of the coating,The tensile strength at room temperature was tested by universal testing machine,and the high temperature endurance strength was tested by high temperature durability testing machine.The results show that the thickness of NiCoCrAlYTa coating is more than 60μm,After heat treatment,the coating is more compact,and metallurgical bonding is obtained between the coating and the substrate due to element diffusion.The phase structure of NiCoCrAlYTa coating is mainly composed of γ'-Ni₃Al/γ-Ni.NiCoCrAlYTa coating has little effect on the room temperature tensile properties and high temperature smooth endurance properties of DZ22B substrate,but it can meet the application requirements.At 1 050 ℃,a dense oxide layer was formed on the surface of NiCoCrAlYTa coating,which slows down the oxidation rate.The oxidation rate of the coating is half of DZ22B substrate.After coated with NiCoCrAlYTa coating of DZ22B substrate,the resistance of gas hot-corrosion at 950℃was increased by 225 times.