Journal ArticleDOI
Oxidation of Tungsten
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TLDR
In this article, the rate of formation of the inner oxide is presumably inversely proportional to its thickness, and an overall rate equation covering the whole range is obtained by combining the rate laws of the two individual processes.Abstract:
Two oxide layers form during the oxidation of tungsten between 700° and 1000°C. The outer layer is porous, powdery, yellow tungstic oxide, , and the inner layer is a dense, thin, dark‐blue, tightly adherent oxide of uncertain composition. The oxidation reaction follows initially the parabolic rate law, but eventually there is a transition to the linear rate law. The rate of formation of the inner oxide is presumably inversely proportional to its thickness. The inner oxide seems to transform to the outer oxide at a constant rate. Upon combining the rate laws of the two individual processes, an overall rate equation covering the whole range is obtained. The thickness of the inner layer tends to a limiting value when the rate of its formation is equal to the rate of transformation to the outer layer.read more
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Journal ArticleDOI
The oxidation of alloys
TL;DR: A review of principles governing alloy oxidation is presented together with the means by which practical oxidation-resistance alloys have been developed in this paper, where an attempt is made to show how the development of oxidation theory has contributed to this effort by a term now referred to as "informed empiricism".
Journal ArticleDOI
Oxidation of tungsten and tungsten carbide in dry and humid atmospheres
TL;DR: In this article, the chemical state and thickness of tungsten oxide products were determined by ESCA, and it was found that the thickness of the oxide layer increases with increased humidity.
Journal ArticleDOI
Comparison of the oxidation behaviour of two dense hot isostatically pressed tantalum carbide (TaC and Ta2C) Materials
TL;DR: The behavior of the two carbides is characterized by the growth of a non-protective oxide scale which, on square section samples, forms a maltese cross as mentioned in this paper, and the formation of tantalum hemipentoxide βTa2O5.