Investigation of thermally sprayed NiCrAlY/TiO 2 and NiCrAlY/Cr 2 O 3 /YSZ cermet composite coatings on titanium alloys
Abstract The present work investigates the hot corrosion behavior of thermally sprayed 65 pct NiCrAlY + 35 pct TiO 2 and 65 pct NiCrAlY + 30 pct Cr 2 O 3 + 5 pct YSZ coatings on titanium 15 alloys. The coatings on the titanium 15 alloy substrates exhibit a near-uniform, dense, and adherent microstr...
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Published in | Engineering Research Express Vol. 4; no. 2; p. 25049 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
01.06.2022
|
Online Access | Get full text |
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Summary: | Abstract
The present work investigates the hot corrosion behavior of thermally sprayed 65 pct NiCrAlY + 35 pct TiO
2
and 65 pct NiCrAlY + 30 pct Cr
2
O
3
+ 5 pct YSZ coatings on titanium 15 alloys. The coatings on the titanium 15 alloy substrates exhibit a near-uniform, dense, and adherent microstructure with a porosity of 2.7 to 2.9%. Thermogravimetric studies are made to examine the hot corrosion performance of coatings in a molten salt environment of Na
2
SO
4
+ 60%V
2
O
5
at the temperature of 700 °C for 50 cycles. One cycle is carried out by heating for a period of one hour and cooling the sample at ambient conditions. The corrosion products are analyzed based on scanning electron microscopy, energy dispersive analysis, and X-ray diffraction techniques to study the morphology, phase composition, and abundance of the high-temperature corrosion constituents. The bare titanium-15 alloy, 65 pct NiCrAlY + 35 pct TiO
2
coating and 65 pct NiCrAlY + 35 pct Cr
2
O
3
+ 5 pct YSZ coating produced a weight gain of 307.92 mg cm
−2
, 42.16 mg cm
−2
and 44.02 mg cm
−2
respectively after the period of 50 cycles. The effective resistance of the coatings is due to the formation of Ni
3
V
2
O
8
, NiCr
2
O
4
, Cr
2
O
3
& AlV
2
O
4
phases. |
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ISSN: | 2631-8695 2631-8695 |
DOI: | 10.1088/2631-8695/ac7946 |