Effect of Annealing Temperature on the Surface Structure and Properties of Porous TiNi
— The phase composition of porous titanium nickelide alloys annealed at temperatures from 500 to 1000°C with a 100°C step has been determined by X-ray diffraction, energy dispersive X-ray spectroscopy, and scanning electron microscopy. Annealing at temperatures in the range 900–1000°C was shown to r...
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Published in | Inorganic materials Vol. 57; no. 12; pp. 1242 - 1249 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Moscow
Pleiades Publishing
01.12.2021
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | —
The phase composition of porous titanium nickelide alloys annealed at temperatures from 500 to 1000°C with a 100°C step has been determined by X-ray diffraction, energy dispersive X-ray spectroscopy, and scanning electron microscopy. Annealing at temperatures in the range 900–1000°C was shown to result in the formation of a double surface layer 4 μm in average thickness as a consequence of titanium segregation and oxidation. The outer layer, up to 2 μm in thickness, consisted of TiO
2
, and the inner, intermetallic layer, up to 3 μm in thickness, was titanium-deficient. A comparative analysis led us to conclude that the outer protective layer formed on the porous alloy as a result of self-propagating high-temperature synthesis effectively prevented oxidation of the TiNi matrix and titanium segregation during annealing in air at temperatures of up to 900°C. Captive bubble wettability measurements showed that the growth of a surface TiO
2
phase at increased annealing temperatures led to higher surface hydrophilicity and an increase in surface free energy. |
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ISSN: | 0020-1685 1608-3172 |
DOI: | 10.1134/S0020168521120050 |