Results 221 to 230 of about 3,969 (258)

Oxidation of niobium aluminide NbAl3

Materials Science and Engineering: A, 1989
Abstract The oxidation of the intermetallic compound NbAl 3 and of materials with some excess aluminium (NbAl 3 + Al) was investigated at temperatures between 650 and 1200 °C in He − 133.3 mbar O 2 . At temperatures between 1000 and 1200 °C, the NbAl 3 single phase shows a quasi-linear oxidation rate caused by cracking and spallation of the ...
M Steinhorst, H.J Grabke
openaire   +1 more source

The Microtopography of Oxide Films on Niobium

Journal of The Electrochemical Society, 1958
An electron microscopic study of the oxide films formed on niobium permits the apparently anomalous oxidation rate behavior of niobium to be explained in terms of the formation of small, blister-like cracks in the oxide film. An oxidation model, based on the idea that an oxidation process which is maintained by interstitial-anion or anion-vacancy ...
J. V. Cathcart, J. J. Campbell, G. P. Smith   +2 more
openaire   +1 more source

Thermodynamic Properties of Niobium Oxides

Journal of Chemical & Engineering Data, 2010
Thermodynamic properties of three oxides of niobium have been measured using solid state electrochemical cells incorporating yttria-doped thoria (YDT) as the electrolyte in the temperature range T = (1000 to 1300) K. The standard Gibbs energies of formation of NbO, NbO2, and NbO2.422 from the elements can be expressed as: Delta(f)G(NbO)(o) +/- 547/J ...
Jacob, KT, Shekhar, Chander, Vinay, M, Waseda, Yoshio   +3 more
openaire   +1 more source

Effect of boronizing on the oxidation of niobium

International Journal of Refractory Metals and Hard Materials, 2013
Abstract Niobium (Nb) and its alloys are used in various industrial applications including metal processing, nuclear power generation and manufacturing of metallic superconductors and rocket nozzles. Although it is resistant to corrosion in several liquid media, Nb has a high oxidation rate in environments such as air at temperatures above 400 °C. In
Ozyigit, M. B., DOKUMACI ALKAN, ESRA, ÖZKAN, İLKER, Onay, B.   +3 more
openaire   +2 more sources

The oxidation of niobium single crystals

Acta Metallurgica, 1969
Abstract Single crystals of niobium in the form of 1 4 -in. dia. spheres have been oxidised in dry oxygen at approximately 400 torr pressure in the temperature range 550–925°C. The results indicate that suboxide platelets are present at temperatures below 600°C, and produce lines of pores in the scale, as reported for tantalum. The lines of pores
openaire   +1 more source

EELS Investigations of Reference Niobium Oxides and Anodically Grown Niobium Oxide Layers

Microscopy and Microanalysis, 2007
Bach, D., Störmer, H., Schneider, R., Gerthsen, D., Sigle, W.   +4 more
openaire   +2 more sources

Application of niobium oxides as catalysts

Catalysis Today, 1990
Abstract Characteristics of niobium oxides as a promoter of various catalysts, a catalyst support, and a unique solid acid catalyst is reviewed. The pronounced effects as a promoter and a support of catalysts for diversified reactions are demonstrated and the strongly acidic nature of hydrated niobium oxide and its application as an unusual ...
openaire   +1 more source

In-situ formation of niobium oxide – Niobium carbide – Reduced graphene oxide ternary nanocomposite as an electrochemical sensor for sensitive detection of anticancer drug methotrexate

Journal of Colloid and Interface Science, 2023
Syang-Peng Rwei, Shen-Ming Chen, Ganesan Muthusankar   +2 more
exaly  

Methods to partially reduce a niobium metal oxide and oxygen reduced niobium oxides

2002
KIMMEL JONATHON L, KITCHELL RICKY W, FIFE JAMES A   +2 more
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Redox properties of niobium oxide catalysts

Catalysis Today, 1996
Goutam Deo, I E Wachs
exaly