Alloy depletion profiles resulting from the preferential removal of the less noble metal during alloy oxidation

1978 ◽  
Vol 12 (5) ◽  
pp. 413-438 ◽  
Author(s):  
B. D. Bastow ◽  
D. P. Whittle ◽  
G. C. Wood
Author(s):  
R. R. Dils ◽  
P. S. Follansbee

Electric fields have been applied across oxides growing on a high temperature alloy and control of the oxidation of the material has been demonstrated. At present, three-fold increases in the oxidation rate have been measured in accelerating fields and the oxidation process has been completely stopped in a retarding field.The experiments have been conducted with an iron-base alloy, Pe 25Cr 5A1 0.1Y, although, in principle, any alloy capable of forming an adherent aluminum oxide layer during oxidation can be used. A specimen is polished and oxidized to produce a thin, uniform insulating layer on one surface. Three platinum electrodes are sputtered on the oxide surface and the specimen is reoxidized.


Author(s):  
Sooho Kim ◽  
M. J. D’Aniello

Automotive catalysts generally lose-agtivity during vehicle operation due to several well-known deactivation mechanisms. To gain a more fundamental understanding of catalyst deactivation, the microscopic details of fresh and vehicle-aged commercial pelleted automotive exhaust catalysts containing Pt, Pd and Rh were studied by employing Analytical Electron Microscopy (AEM). Two different vehicle-aged samples containing similar poison levels but having different catalytic activities (denoted better and poorer) were selected for this study.The general microstructure of the supports and the noble metal particles of the two catalysts looks similar; the noble metal particles were generally found to be spherical and often faceted. However, the average noble metal particle size on the poorer catalyst (21 nm) was larger than that on the better catalyst (16 nm). These sizes represent a significant increase over that found on the fresh catalyst (8 nm). The activity of these catalysts decreases as the observed particle size increases.


Author(s):  
Yaru Li ◽  
Yu-Quan Zhu ◽  
Weili Xin ◽  
Song Hong ◽  
Xiaoying Zhao ◽  
...  

Rationally designing low-content and high-efficiency noble metal nanodots offers opportunities to enhance electrocatalytic performances for water splitting. However, the preparation of highly dispersed nanodots electrocatalysts remains a challenge. Herein, we...


Alloy Digest ◽  
1957 ◽  
Vol 6 (1) ◽  

Abstract CARILLOY 2% Cr-1/2% Mo is a low alloy oxidation and corrosion resistant steel suitable for moderately high (900-1100 deg. F.) temperature use. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-54. Producer or source: United States Steel Corporation.


2019 ◽  
Vol 55 (5) ◽  
pp. 832-838 ◽  
Author(s):  
T. N. Matveeva ◽  
V. V. Getman ◽  
M. V. Ryazantseva ◽  
A. Yu. Karkeshkina ◽  
L. B. Lantsova

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