1. Mechanically Alloyed Oxide Dispersion Strengthened Metals

2. Atom probe image of MA957

3. MA956 Chou & Bhadeshia, 1994

4. MA956 Chou & Bhadeshia, 1994

5. o o A B A B 1-x Gibbs free energy per mole Concentration x of B   free energy of mechanical mixture G* x Mechanical Mixture

6. o o A B A B x Gibbs free energy per mole Composition   G{x} free energy of mechanical mixture ∆G M free energy of solution G*

7. +=

9. For a random mixture, number of configurations given by:

10. Boltzmann

12. Classical theory for entropy of mixing

13. Solution-like behaviour when particles about 1000 atoms in size Free energy of mixing due to configurational entropy alone

14. Enthalpy

15. Surface per unit volume SvSv Particle size Solution formation impossible!

16. coherent incoherent

17. Single barrier to solution formation when components attract Badmos and Bhadeshia, 1997

18. Double barrier to solution formation when components immiscible Badmos and Bhadeshia, 1997

19. o o A B A B Composition   free energy of solution

20. o o A B A B Gibbs free energy per mole   Concentration x of B Paradox at concentration extremities vanishes in the discrete model of concentration