Improving the oxidation behavior of low expansion Ni plus CrAlYNO coating systems by regulating the oxygen content

The three duplex coatings comprised inner NiCrAlY layer and outer Ni + CrAlYNO cermet layer, which were referred to as N + 10O, N + 20O and N + 30O based on the oxygen content of flowing into the cermet layer, were prepared by a vacuum arc evaporation machine using a NiCrAlY target. Upon oxidation, the inclusion of YAG inside the alumina and the formation of non-alumina were detected in the N + 10O and N + 20O coatings. In comparison, the N + 30O coating through the slow growth rate and few impurities of TGO appeared superior oxidation resistance. This was mainly due to oxygen content on coatings degradation and Y distribution.

Automated summary

The study found that the duplex coatings of NiCrAlY layer and Ni + CrAlYNO cermet layer exhibited different characteristics during oxidation, with the N + 30O coating showing superior oxidation resistance.