Nickel, passivation

Yellow brass Admiralty brass Aluminum bronze Red brass Copper Silicon bronze 70-30 cupronickel Nickel (passive)... 

Phillips Petroleum developed antimony for nickel passivation. 

Nickel passivation is generally economically attractive when the nickel content of the E-cat is greater than 1,000 ppm. The Phillips Petroleum secondary antimony patent position is due to expire in l uc 1999, At that time, antimony passivation can become economically attractive at a lower nickel level than 1,000 ppm. 

NiS04 7H20. 330g/1 Nickel Passive Pitting 0 + 0-08... 

Figure 39. Current-time variation in nickel pitting dissolution in NaCl solution.89,91 1, double-layer charging current 2, fluctuation-diffusion current 3, minimum dissolution current 4, pit-growth current (Reprinted from M. Asanuma andR. Aogaki, Nonequilibrium fluctuation theory on pitting dissolution. II. Determination of surface coverage of nickel passive film, J. Chem. Phys. 106, 9938, 1997, Fig. 2. Copyright 1997, American Institute of Physics.)...

Use a catalyst with built-in nickel passivation when nickel is above 1500 ppm or hydrogen production is above 0.13 wt% on fresh feed... 

This suggests that the passivity is due to a layer of oxide forming on the surface of the metal and protecting the underlying portions from attack. Such, very possibly, is one explanation, but apparently it does not account for all cases of nickel passivity. Thus Schmidt and Rathert11 have passivified nickel by friction in an atmosphere of... 

The electrochemical oxidation of the nickel is of special interest since it is a typical passivation metal in which very thin passive oxide films of a few nm thickness on the surface can cover the substrate metals efficiently. The passive oxide layer on the nickel was studied by Sikora and Mac Donald [118] who claimed that the passive film consisted of the inner nickel oxide of a barrier layer and an outer Ni(OH)2 porous or hydrated layer, in which the inner layer behaves as a p-type oxide with a cation vacancy. Oblonsky and Devine measured the surface enhanced Raman spectra of the nickel passivized in a neutral borate solution and estimated the amorphous Ni(OH)2 in the passive potential region and the NiOOH in the higher transpassive region [119]. Further, the passive films formed in the acidic and neutral solutions were assumed as partially hydrated nickel oxide [120,121]. The anodic film formed in the alkaline solution was assumed to be Ni(OH)2 in the... 

Cupro Nickel G-Bronze M-Bronze Silver Solder Nickel (Passive)... 

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