• Title/Summary/Keyword: Elasto-diffusive phenomena

Search Result 2, Processing Time 0.018 seconds

Fundamentals of Stress-Induced Diffusion: Theoretical Approach to Hydrogen Transport through Self-Stressed Electrode

  • Lee, Sung-Jai;Pyun, Su-Il
    • Journal of the Korean Electrochemical Society
    • /
    • v.8 no.1
    • /
    • pp.47-54
    • /
    • 2005
  • This article covers the fundamentals of stress-induced diffusion, focusing on the theoretical model for hydrogen transport through self-stressed electrode. First, the relationship between hydrogen diffusion and macroscopic deformation of the electrode specimen was briefly introduced, and then it was classified into the diffusion-elastic and elasto-diffusive phenomena. Next, the transport equation for the flux of hydrogen caused simultaneously by both the concentration gradient and the stress gradient was theoretically derived. Finally, stress-induced diffusion was discussed on the basis of the numerical solutions to the derived transport equation under the permeable and impermeable boundary conditions.

Application of Laser Beam Deflection Technique to Analysis of Stresses Generated during Hydrogen Diffusion through Pd Foil Electrode

  • Han Jeong-Nam;Pyun Su-Il
    • Journal of the Korean Electrochemical Society
    • /
    • v.4 no.2
    • /
    • pp.70-76
    • /
    • 2001
  • The present work describes the capabilities of laser beam deflection (LBD) technique for the analysis of the stresses developed during hydrogen diffusion through Pd foil electrode. First, we explain briefly the elasto-diffusive (Gorsky effect) and diffusion-elastic phenomena. A model for the diffusion-elastic phenomenon is theoretically derived from the solution of the Fick's equation for given initial and boundary conditions, Vegard's second law and Hooke's law. Second, we introduce how to apply the principle of LBD technique to the study on the stresses generated during hydrogen diffusion. From the comparison of the deflection transients numerically calculated with those experimentally measured, we finally discuss the change in the tensile deflection with time in terms of hydrogen concentration profile transient and hydrogen diffusivity.