Chapter 3-5

Question 1

Bulk or volume diffusion

Answer 1

Motion of atoms through the body of a medium.

Question 2

Vacancy Diffusion

Answer 2

Atoms jump into vacancies.

Question 3

Vacancy. Small and/or Large

Answer 3

Small and large

Question 4

Interstitial Diffusion

Answer 4

Atoms jump in interstitial spaces.

Question 5

Interstitial. Small and/or Large

Answer 5

Only small. Have to squeeze in between

Question 6

Surface Diffusion

Answer 6

Atoms along surfaces within the medium

Question 7

Grain Boundary and Phase boundary diffusion

Answer 7

Grains create the lines in a crystal.

Question 8

Increases diffusive flow

Answer 8

High temperature, long times, small diffusing species, medium through which diffusion occurs is not densely packed, greater concentration gradients

Question 9

Choose. Increase temperature or time

Answer 9

Temperature

Question 10

Fick’s First Law

Answer 10

Concentration must not change after diffusion. Activation energy must be overcome to move to new location.

Question 11

True of False. Q of vacancy tends to be smaller than Q of interstitial

Answer 11

False.

Question 12

Fick’s Second Law

Answer 12

Concentration changes as a function of time within the medium

Question 13

What activates diffusion

Answer 13

Temperature

Question 14

What drives diffusion

Answer 14

Concentration gradients

Question 15

Stiffness

Answer 15

Ability to resist ELASTIC deformation

Question 16

Strength

Answer 16

Ability to resist permanent PLASTIC deformation

Question 17

Ductility

Answer 17

Ability to deform to large plastic strains

Question 18

Toughness

Answer 18

resistance to fracture

Question 19

Creep Resistance

Answer 19

resistance to high temperature deformation

Question 20

Fatigue Strength

Answer 20

Resistance to cyclic loading