WANG Fuhui LOU Hanyi WU Weitao Corrosion Science Laboratory
,
Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
China Research Assistant
,
Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
An investigation was carried out of the resistance to cyclic oxidation of the as-cast normal-grained Co-30Cr-5Al alloy substrate at 1000℃ in air together with its sputtered coating of microcrystallized CoCrAl alloy grains sized less than 0.5μm.Acoustie emissi on counts showed that the initially formed Al_2O_3 scale on the bare alloy substrate cracked and spalled severely off after only one or two cycles on cooling and then the worse protective layer of Cr_2O_3 and CoCr_2O_4 spinel occurred on surface.While such substrate coated with sputtered microcrystallized CoCrAl alloy film was not damaged under oxidation even through 100 cycles at 1000℃.In comparison with the normal-grained alloy,the microcrystallized al- loy,coating of similar constitution exhibite excellent resistance to oxide spalling on surface.
关键词:
microcrystallized CoCrAl coating
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WANG Fuhui LOU Hanyi WU Weitao Corrosion Science Laboratory
,
Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
China associate professor
,
Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
Effect of a sputtered Co-30Cr-5Al microcrystalline coating on oxidation resistance of intermetallic compound TiAl and oxidation behavior of the bare TiAl were investigated at 900—1000℃ in static air.The oxidation kinetics for the TiAl alloy seems to approximately follow a linear rate law.Poor oxidation resistance of TiAl is due to the formation of the mixed Al_2O_3+TiO_2 scale which is loosely packed and easily spalled off.but not of dense and adherent pure Al_2O_3.A sputtered Co-30Cr-5Al coating,30 μm thickness,can remarkably improve the oxidation resistance of TiAl owing to the formation of adherent Al_2O_3 protective scale.However,many Kirkendall voids were formed between coating and substrate.
关键词:
CoCrAl microcrystalline coating
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