| Segregation Science |
|
|
Segregation is not only a large field, it is also not easily ploughed. Since it
is instrumental for wootz blades, I will devote several science modules and two special
modules to this topic.
- Basics of Segregation.
Topics covered are: 1. Some basics about
segregations. 2. Phase diagrams, "macroscopic" segregation and the segregation coefficient. 3. The flow of energy
and particle currents through the solid-liquid interface during freezing - and what it implies.
- Constitutional Supercooling and Interface Stability
Topics covered
are: 1. Non-equilibrium and how systems try to get back to equilibrium. Exploiting the difference between currents and current
densities. 2. What is constitutional supercooling and calculations for a simple model. 3. Supercooling, interface stability
and dendritic growth plus some remarks to convection in the melt.
- Supercooling and Microstructure.
Topics covered are: 1 How supercooling
plus segregation determines the microstructure of the forming solid. 2. A closer look at what happens when we cast an object.
3. Temperature gradient and interfaces velocity are the most important parameters for the microstructure.
- 4. Segregation at High and Ambient Temperatures
Topics covered are:
1 What could happen during cooling. 2. A simple model for macrosegregation at high temperatures 3. Microsegregation at high
temperatures. 4. What is left at room temperature and a simple way to look at the effects of diffusion. The importance of
microsegregation for the nucleation of precipitates.
- Striations.
Striations, an universal expression of microsegregation,
are necessary for wootz steel patterns but not contained in the preceding modules. Examples are given and discussed.
|
|
Related modules are:
- Segregation and Striations in CZ Silicon.
Showing that segregation
can have major effects - even in almost perfect crystals with very small impurity concentrations - and that it occurs typically
in the form of striations
- Microsegregation and "Current Burst" theory.
Comparing self-organizing features of Si electrochemistry to self-organization features of liquid-solid interfaces, speculating
that striations are expressions of stochastic events synchronized by nearest neighbor interactions. |
|
| |
With frame
Glossary
6.2.2 Solidification and the Art of Casting
Science of Welding Steel
The Verhoeven - Wadsworth Jousting Tournament
11.5.2 Structure by Dendrites?
Segregation at Room Temperature
10.4. Crucible Steel 10.4.1 The Making of Crucible Steel in Antiquity
Segregation in Silicon
Powder Metallurgy
1. Basics of Segregation
Constitutional Supercooling
Segregation at Room Temperature
Microsegregation and "Current Burst" Theory
Constitutional Supercooling and Interface Stability
TTT Diagrams 4. Experimental Construction of TTT and Phase Diagrams
© H. Föll (Iron, Steel and Swords script)