Oxide formation on sputtered Ni-3Cr-10Al nanocrystalline coating①
(State Key Laboratoryfor Corrosion and Protection of Metals, Institute of Corrosion and
Protection of Metals, Chinese Academy of Sciences, Shenyang110015, P.R.China)
Protection of Metals, Chinese Academy of Sciences, Shenyang110015, P.R.China)
Abstract: The oxide formation on the sputtered Ni-3Cr-10Al nanocrystalline coating at 900℃and 1 000℃in air has been studied. The results indicated that an oxide scale composed of NiAl2O4and Al2O3was formed on the sputtered Ni-3Cr-10Al nanocrystalline coating whereas a unitary Al2O3scale was not formed even when the Al content was high in the sputtered coating. The formation of NiAl2O4was directly related to the precipitation of Ni3Al in the coating during oxidation process. It was suggested that the precipitation of Ni3Al contributed to the formation of NiO and therefore NiO could react with Al2O3and form NiAl2O4. With increasing oxidation temperature, the effect of Ni3Al precipitation on the formation of NiAl2O4decreased.
Key words: Ni-3Cr-10Al; sputtering; nanocrystalline coating; oxidation