Ostwald Ripening and Phase Transformations

These flashcards cover the key concepts discussed in the lecture related to Ostwald ripening, phase transformations, nucleation types, and properties affecting materials behavior.

What does Ostwald ripening refer to in phase transformations?

The process where small particles dissolve and larger particles grow, leading to an increase in average particle size over time.

What is the significance of surface energy in materials?

Metals have a higher surface energy than plastics due to dangling bonds.

What are the two types of nucleation in phase transformations?

Homogeneous nucleation and heterogeneous nucleation.

What factors can affect nucleation growth?

Nucleation growth is influenced by energy levels in diffusive components.

What is the relation between temperature and free volume in glass transition?

Free volume increases with temperature, affecting the solidification process.

According to Fick's 1st Law, what is flux a function of?

Flux is a function of the concentration gradient and the diffusion coefficient.

What is interstitial diffusion?

Diffusion where larger lattice atoms move, not necessarily related to concentration.

What do Schottky defects involve?

They involve vacancies created by the removal of ion pairs, a type of intrinsic point defect.

What happens during spinodal decomposition?

Longer polymer chains lead to less entropy, acting as a driving force to mix.

How is the diffusion coefficient for gases compared to liquids and solids?

For gases, it's about 1 cm/s, for liquids around 10^-5 to 10^-4 cm/s, and for solids about 10^-10 cm/s.