Closure to “Discussion of ‘The Origin of the Cubic Rate Law in Zirconium Alloy Oxidation’ [G. P. Sabol and S. B. Dalgaard (pp. 316–317, Vol. 122, No. 2)]”

1975 ◽  
Vol 122 (12) ◽  
pp. 1745-1745
Author(s):  
G. P. Sabol ◽  
S. B. Dalgaard
Keyword(s):  
Zirconium Alloy ◽  
Rate Law ◽  
Alloy Oxidation ◽  
Cubic Rate Law

The Origin of the Cubic Rate Law in Zirconium Alloy Oxidation

1975 ◽  
Vol 122 (2) ◽  
pp. 316-317 ◽  
Author(s):  
G. P. Sabol ◽  
S. B. Dalgaard
Keyword(s):  
Zirconium Alloy ◽  
Rate Law ◽  
Alloy Oxidation ◽  
Cubic Rate Law

scholarly journals Rapid assessment of structural and compositional changes during early stages of zirconium alloy oxidation

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Elizabeth J. Kautz ◽  
Bharat Gwalani ◽  
Sten V. M. Lambeets ◽  
Libor Kovarik ◽  
Daniel K. Schreiber ◽  
...  
Keyword(s):  
Zirconium Alloy ◽  
Rapid Assessment ◽  
Atom Probe ◽  
Chemical Imaging ◽  
Atomic Scale ◽  
Short Exposure ◽  
Metal Interface ◽  
Structure Changes ◽  
Alloy Oxidation ◽  
Scanning Transmission

Abstract A multimodal chemical imaging approach has been developed and applied to detail the dynamic, atomic-scale changes associated with oxidation of a zirconium alloy (Zircaloy-4). Scanning transmission electron microscopy, a gas-phase reactor chamber attached to an atom probe tomography instrument, and synchrotron-based X-ray absorption near-edge spectroscopy were employed to reveal morphology, composition, crystal, and electronic structure changes that occur during initial stages of oxidation at 300 °C. Oxidation was carried out in 10 mbar O2 gas for short exposure times of 1 and 5 min. A multilayered oxide film with a cubic ZrO adjacent to the oxide/metal interface, a nanoscopic transition region with a graded composition of ZrO2−x (where 0 < x < 1), and tetragonal ZrO2 in the outermost oxide were formed. Partitioning of the major alloying element (tin) to the oxide/metal interface and heterogeneously within the oxide accompanied the development of the layered oxide. Our work provides a rapid, high-throughput approach for detailed characterisation of initial stages of zirconium alloy oxidation at an accelerated time scale, with implications for several other alloy systems.

Scanning Electron Microscopy of an 8 μm Thick ZrO2 Film

1977 ◽  
Vol 35 ◽  
pp. 266-267
Author(s):  
R.A. Ploc ◽  
M.A. Miller
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silica Gel ◽  
Zirconium Alloy ◽  
Oxide Thickness ◽  
Breakaway Oxidation ◽  
Zro2 Film ◽  
Alloy Oxidation ◽  
One Year ◽  
Scanning Electron

This abstract reports the occurrence of 'breakaway oxidation' for unalloyed zirconium in 300°C oxygen. An excellent review of zirconium and zirconium alloy oxidation can be found elsewhere (1).Approximately one dozen crystal bar zirconium coupons were placed in a resistance wound furnace held at 300°C and through which oxygen (initially passed through a silica gel dessicant) was passed. Over a period of three years, the samples accumulated over 700 days of oxidation time. The kinetics followed a rate law between cubic and parabolic until achieving an oxide thickness approximately 350 nm at which point 'breakaway' occurred. For instance, in one year the film increased in thickness from 0.35 to more than 8 μm. These thick, post-transition oxides were examined in the SEM.The samples were characterized by regions approximately 40 μm in diameter which spalled with a density of about 45 per cm2.

Towards a better understanding of the oxide film growth mechanism in E110 zirconium alloy under high-temperature oxidation in steam

2020 ◽  
Vol 38 (2) ◽  
pp. 165-181
Author(s):  
Andrey B. Rozhnov ◽  
Hannanh Alsheikh ◽  
Sergey A. Nikulin ◽  
Vladislav A. Belov ◽  
Elina V. Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxide Film ◽  
Zirconium Alloy ◽  
High Temperature Oxidation ◽  
Film Growth ◽  
Surface Oxide Film ◽  
Temperature Oxidation ◽  
Interface Growth ◽  
White Spots ◽  
Alloy Oxidation

AbstractHigh-temperature oxidation of E110 (Zr-1%Nb) zirconium alloy in steam at Т = 1100°C to various degrees has been carried out. Based on the studies of morphology and microstructure of the oxide film and metal, as well as on review of previously published results, the mechanism of alloy oxidation has been proposed, which includes oxide thickening close to the oxide/metal interface, growth of the thickened areas and their conversion into nodules, growth of the nodules and crowning of the metal surface (white spots), clustering of nodules under the formed oxide, formation of a double (white on the surface) oxide film and delamination of the oxide upper layer.

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