chp5 - 1 Chapter 5- Slides adapted from J Wiley material...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 Chapter 5- Slides adapted from J Wiley material ISSUES TO ADDRESS... How does diffusion occur? Why is it an important part of processing? How can the rate of diffusion be predicted for some simple cases? 1 How does diffusion depend on structure and temperature? CHAPTER 5: DIFFUSION IN SOLIDS Chapter 5- Slides adapted from J Wiley material 2 Glass tube filled with water. At time t = 0, add some drops of ink to one end of the tube. Measure the diffusion distance, x, over some time. Compare the results with theory. DIFFUSION DEMO 2 Chapter 5- Slides adapted from J Wiley material 3 Interdiffusion : In an alloy, atoms tend to migrate from regions of large concentration. Initially After some time 100% Concentration Profiles Adapted from Figs. 5.1 and 5.2, Callister 6e . DIFFUSION: THE PHENOMENA (1) Chapter 5- Slides adapted from J Wiley material 4 Self-diffusion : In an elemental solid, atoms also migrate. Label some atoms After some time A B C D DIFFUSION: THE PHENOMENA (2) 3 Chapter 5- Slides adapted from J Wiley material 5 Substitutional Diffusion: applies to substitutional impurities atoms exchange with vacancies rate depends on:--number of vacancies--activation energy to exchange. DIFFUSION MECHANISMS Chapter 5- Slides adapted from J Wiley material The rate of diffusion should 1. increase with temperature 2. decrease with temperature 3. not depend on temperature 4 Chapter 5- Slides adapted from J Wiley material 6 Simulation of interdiffusion across an interface: Rate of substitutional diffusion depends on:--vacancy concentration--frequency of jumping.--frequency of jumping....
View Full Document

Page1 / 12

chp5 - 1 Chapter 5- Slides adapted from J Wiley material...

This preview shows document pages 1 - 5. Sign up to view the full document.

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