Study on Oxidation Property of TiAl/NiCoCrAl Microlaminated Sheet Prepared by EB-PVD

Abstract:

TiAl/NiCoCrAl microlaminated sheet prepared by EB-PVD have been oxygenized in air at 850 oC, and its oxidation property has been studied. The phase composition and microstructure have been analyzed by XRD and SEM. The results show TiAl/NiCoCrAl microlaminated sheet has good oxidation resistance and the oxidation kinetics curves follow the parabolic law. The oxidation mechanisms of TiAl/NiCoCrAl microlaminated sheet at high temperature is that Al on the surface will generate the Al2O3 monolayer oxide film with porous structure firstly, subsequently some Ti element in the inner TiAl layers will cross over the NiCoCrAl layers and reach the surface to generate the (TiO2 + Al2O3) oxide layer, and finally Ni and Cr in the NiCoCrAl layers can generate compact outer oxide film composed of Cr2O3 and NiCr2O4 phase, which is the essential reason why the oxidation resistance of the sheet increases obviously.

Key words:TiAl/NiCoCrAl; microlaminated sheet; EB-PVD; oxidation property