Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (28권3호 142-151)

The effect of Cr coated on the Ni and Inconel 601 substrate by PECVD on the oxidation behavior at high temperature

PECVD법으로 증착한 Cr코팅층이 Inconel 601과 Ni의 내산화성에 미치는 영향

강옥경;정명모;김길무;

충남대학교 공과대학 재료공학과, 충남대학교 급속응고신소재연구소;한국원자력안전기술연구원;

Abstract

In this research, a thin layer of Cr was coated on the pure Ni and Inconel 601 by PECVD (Plasma Enhanced Chemical Vapor Deposition) in order to study the effect of Cr on the oxidation behavior at high temperature. Cr coated Inconel 601, which was oxidized at $1100^{circ}C$ for 24 hours, formed a protective $Cr_2O_3$ oxide layer and the resistance to isothermai oxidation was improved. On the other hand, oxidation resistance of Cr coated Inconel 601 at 100$0^{circ}C$ was not significantly improved, probably due to the formation or insufficient $Cr_2O_3$ layer. But, when oxidized at $1000^{circ}C$ and $1100^{circ}C$ for 100 hours, Cr coated Inconel 601 improved isothermal oxidation resistance by the formation of continuous $Cr_2O_3$ external scale and by the development of $Al_2O_3$ subscales. Cr coated Ni formed inner layer of $Cr_2O_3$ within almost pure NiO, which provided additional cation vacancies, thus increasing the mobility of Ni ions in this region. It is believed that this doping effect resulted in an increase in the observed oxidation rate compared with pure Ni and did not improve the oxidation resistance.

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