Ex03 Diffusion Structures and Properties of materials

EGN3365

Activation Energy

minimum energy required for a chemical reaction to occur.

Carburizing

Diffuse carbon atoms into host iron atom at the surface. increases the hardness and wear resistance of the iron.

Diffusion

movement of atoms within a material

Diffusion coefficient

D [m²/2]

Diffusion flux

J=M/At

Ficks First Law

high concentration to low concentration

Ficks second Law

prediction of change in concentration gradient with time due to diffusion

Interstitial diffusion

smaller attoms diffuse between atoms (more rapid then vacancy diffusion)

Non steady-state diffusion

a time dependent process in which the rate of diffusion is a function of time

Self-diffusion

In an element solid atoms also migrate.

Steady-state diffusion

the net movement of a species down a concentration gradient, from an area of high concentration to an area of low concentration

Vacancy diffusion

atoms exchange with vacancies.