Chapter 5_Part_3

Chapter 5_Part_3 - Nonsteady-State Diffusion: Ficks second...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
11 MSE 2090: Introduction to Materials Science Chapter 5, Diffusion Nonsteady-State Diffusion: Fick’s second law 2 2 x C D t C = Fick’s second law relates the rate of change of composition with time to the curvature of the concentration profile: Concentration increases with time in those parts of the system where concentration profile has a positive curvature. And decreases where curvature is negative. C x C x C x The phenomenological description based on the Fick’s laws is valid for any atomic mechanism of diffusion. Understanding of the atomic mechanisms is important, however, for predicting the dependence of the atomic mobility (and, therefore, diffusion coefficient) on the type of interatomic bonding, temperature, and microstructure.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
12 MSE 2090: Introduction to Materials Science Chapter 5, Diffusion To jump from lattice site to lattice site, atoms need energy to break bonds with neighbors, and to cause the necessary lattice distortions during jump. The energy necessary for
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 5

Chapter 5_Part_3 - Nonsteady-State Diffusion: Ficks second...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online