Micro-electrochemical studies were made of H storage materials (table 111) by using a micro-electrode technique. A filament of C fibre was placed in contact with single particles of the alloys, in 1M KOH solution, by using a micromanipulator. In this way, cyclic voltammetric, potential step experiments and in situ X-ray diffraction experiments could be carried out. The current responses, recorded as a function of time, were analyzed by using a spherical diffusion model.

Determination of Chemical Diffusion Coefficients in Metal Hydride Particles with a Microelectrode Technique. T.Nishina, H.Ura, I.Uchida: Journal of the Electrochemical Society, 1997, 144[4], 1273-8

 

Table 113

Permeability of H in IN718

 

Heat Treatment

Po (mol/msMPa½)

E (kJ/mol)

cold-rolled 75%

0.000198

59.03

980C,2h; a

0.000236

60.19

980C,2h; a; 720C,8h; f; 620C,8h; a

0.000212

59.53

980C,2h; a; 720C,100h; a

0.000259

62.69

a: air-cooled, f: furnace-cooled