1. Materials Science and Metallurgy Course A: Metals & Alloys
Part IB
Materials Science and Metallurgy
Course A: Metals & Alloys
Professor Harry Bhadeshia
Lecture 12:
High Temperature Alloys

5. P122
P23
F. Masuyama

6. Superheater Outlet Header for 30MPa and 630℃
F. Masuyama

7. 0.5 µm

9. matrix

10. Coarsening diffusion r r flux concentration q a q aq c r aq c r1 2
flux q a q
concentration aq c r 1 aq c r 2
distance

11. To minimise coarsening:
Reduce interfacial energy
Reduce diffusivity
Precipitates with low solubility in matrix

13. g  ‘

15. superdislocation

16. Order hardening
Dislocations finding it difficult to penetrate ’
Yanhui Zhang

17. Superdislocations
Hillier, 1984

21. Page 77

22. TiAl 

23. Ti3Al 

24. Ti-48Al at%
Alternating layers of 2 and 
Kim, Maruyama, 2001

25. TiAl 
Daido Steel