ISSN:
1573-4889
Keywords:
OXIDATION
;
Ti3Al-Nb
;
COATINGS
;
SPUTTERED NiCrAlY
;
ION-PLATED TIN
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract A single sputtered NiCrAlY coating and a complexcoating of inner ion-plated TiN and outer sputteredNiCrAlY were prepared on the intermetallic compoundTi3Al-Nb. Their oxidation behavior wasexamined at 850, 900, and 950°C in air by thermalgravimetry combined with XRD, SEM, and EDAX. The resultsshowed that Ti3Al-Nb followed approximatelyparabolic oxi dation, forming an outer thinAl2O3-rich scale and an inner TiO2-rich layer doped withNb at the three temperatures. The TiO2-richlayer doped with Nb dominated the oxidation reaction.The single NiCrAlY coating did not follow parabolicoxidation exactly at 850 and 950°C, but oxidizedapproximately in a parabolic manner, because theinstantaneous parabolic constants changed slightly withtime. Besides the Al2O3 scale,TiO2 formed from the coating surface at the coating-substrate interface. Thedeterioration of the coating accelerated with increasingtemperature. The NiCrAlY-TiN coating showed two-stageparabolic oxidation at 850 and 900°C, and anapproximate parabolic oxidation at 950°C. The TiN layerwas effective as a barrier to inhibit coating-alloyinterdiffusion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1018823901649
