ISSN:
1573-4889
Keywords:
oxidation
;
mechanism
;
Ti-Al alloys
;
Ti-Si alloys
;
nickel-based alloys
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Thermodynamic calculations are performed to estimate isothermal sections of Ti-Al-O, Ti-Si-O, and Ni-Al-O phase diagrams. Very small aluminum levels (〈10−10 at. %) are needed to stabilize alumina on Ni-Al alloys. However, much higher aluminum (≳50%) and silicon (≳40%) levels are needed to stabilize alumina and silica on Ti-Al and Ti-Si alloys, respectively. These calculations suggest that the mechanism of formation of the protective oxide films on titanium-based alloys is radically different from that on nickel-based alloys. The aluminum levels needed to form a continuous film of alumina on nickel-based alloys are dominated by kinetic factors. On the other hand, thermodynamic factors appear to dominate the alloy compositions needed to form protective films of alumina and silica on titanium-based alloys. Further work is needed to evaluate any possible role of kinetic factors.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01151593
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