Study on the Effect of Different Bonding Interlayers on the Performance of Nickel-Based Single Crystal Alloys

In order to address the high-temperature oxidation and corrosion issues of DD6 nickel-based single crystal alloy used in aviation engine high-pressure turbine blades， NiCoCrAlY and PtAl oxidation-resistant coatings were prepared using vacuum arc plating and platinumaluminizing processes， respectively.The effects of these two coatings on the high-temperature oxidation， gas hot corrosion， and mechanical properties of the base material were comparatively studied.Results showed that， compared with the traditional NiCoCrAlY coating， the PtAl coating exhibited superior high-temperature oxidation resistance and gas hot corrosion resistance.This was primarily due to the introduction of Pt， which promoted the rapid oxidation of Al at high temperatures， forming a continuous and dense protective α-Al2 O3 layer.The tensile strength of the NiCoCrAlY coating specimens at 760 ℃showed a slight increase， whereas the tensile strength increase for the PtAl coating specimens under the same testing conditions was significantly lower than that of the NiCoCrAlY coating specimens.After deposition of both coatings， the yield strength of the materials was significantly lower than that of the uncoated specimens， with the yield strength decrease in the PtAl coating specimens being particularly pronounced.This was related to the relatively high ductile-brittle transition temperature of the Ptmodified aluminides.Under the conditions of 980 ℃/250 MPa， both coatings were beneficial in extending the material’s service life， with the NiCoCrAlY coating showing a particularly significant effect.The formation of protective oxides inhibited crack initiation and propagation， which was the primary reason for the extension of the material’s high-temperature service life.