Effect of ion plating TiN on the oxidation of sputtered NiCrAlY-coated Ti{sub 3}Al-Nb in air at 850-950 C

Journal Article · Sat Aug 01 04:00:00 EDT 1998 · Oxidation of Metals

DOI:https://doi.org/10.1023/A:1018823901649· OSTI ID:655366

Rizzo, F C ^[1]; Zeng, C ^[1]; Wu, W ^[2]

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1. Pontificia Univ. Catolica, Rio de Janeiro (Brazil). Dept. de Ciencia dos Materiais e Metalurgia
2. Chinese Academy of Sciences, Shenyang (China). State Key Lab. for Corrosion and Protection

A single sputtered NiCrAlY coating and a complex coating of inner ion-plated TiN and outer sputtered NiCrAlY were prepared on the intermetallic compound Ti{sub 3}Al-Nb. Their oxidation behavior was examined at 850, 900, and 950 C in air by thermal gravimetry combined with XRD, SEM, and EDAX. The results showed that Ti{sub 3}Al-Nb followed approximately parabolic oxidation, forming an outer thin Al{sub 2}O{sub 3}-rich scale and an inner TiO{sub 2}-rich layer doped with Nb at the three temperatures. The TiO{sub 2}-rich layer doped with Nb dominated the oxidation reaction. The single NiCrAlY coating did not follow parabolic oxidation exactly at 850 and 950 C, but oxidized approximately in a parabolic manner, because the instantaneous parabolic constants changed slightly with time. Besides the Al{sub 2}O{sub 3} scale, TiO{sub 2} formed from the coating surface at the coating-substrate interface. The deterioration of the coating accelerated with increasing temperature. The NiCrAlY-TiN coating showed two-stage parabolic oxidation at 850 and 900 C, and an approximate parabolic oxidation at 950 C. The TiN layer was effective as a barrier to inhibit coating-alloy interdiffusion.

• OSTI ID: 655366
• Journal Information: Oxidation of Metals, Journal Name: Oxidation of Metals Journal Issue: 1-2 Vol. 50; ISSN OXMEAF; ISSN 0030-770X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CHROMIUM ALLOYS
INTERMETALLIC COMPOUNDS
KINETICS
NICKEL ALLOYS
NIOBIUM ALLOYS
OXIDATION
PROTECTIVE COATINGS
TITANIUM ALLOYS
TITANIUM NITRIDES
YTTRIUM ALLOYS