1. Microstructure & Performance of Joints in High Temperature Alloys

2. Microstructure & Performance of Joints in Superalloys

3. Shirzadi, Saindrenan & Wallach, 2003
Diffusion Bonding
Pure aluminium
Minimal gallium
Shirzadi, Saindrenan & Wallach, 2003

4. Diffusion Bonding of Gallium -Treated Superalloy Surfaces
3-10 MPa pressure oC
1 h
10-7 bar
1 mg cm-2 gallium

5. 100 µm
Co-23Cr-10 Ni-7W
0.2Ti-0.6C-0.5Zr wt%
Shirzadi & Wallach

6. 50 µm
Ni-15Cr-10Co-9.5Mo
4.2Al-3.6Ti-0.006B wt%
Shirzadi & Wallach

8. Directionally solidified nickel superalloy
Single-crystal nickel superalloy
Shirzadi & Wallach

9. Bonding completed in 1 hour
Shirzadi & Wallach

10. Single-Crystal Repair
Melt shallow layer of SX substrate using laser.
Feed melt pool with alloy powder.
Epitaxial columnar growth.
Repeat to build thicker layers.
Kurz

12. Single-Crystal Repair
Kurz

13. Kurz

14. Single-Crystal Surface Engineering
Lowering Cr improves properties.
Polycrystalline coatings such as NiCrAlY.
Ni is anisotropic.

15. Sieborger et al.
E100 = 125 GPa E111 = 310 GPa

16. Dendrites grow along <100>.
Variant selected is closest to heat flux.
Kurz

17. high aluminium MCrAlY
primary b
low aluminium MCrAlY
primary g

18. MCrAlY
CMSX-4

19. Transient liquid-phase bonding

20. Al-Li
TLP
TG-TLP
Shirzadi & Wallach, 1999

23. TG-TLP Alloy 6082 Large gradient Small gradient
Shirzadi & Wallach, 1999

24. Inertia Welding Process
No liquid phase
Can join dissimilar metals
Powder metallurgical alloy RR1000
Residual stress
Baxter, Preuss, Withers

25. Rolls-Royce
Nottingham

26. Oxide Dispersion Strengthened Metals
Mechanically Alloyed
Oxide Dispersion Strengthened Metals

27. Fine dispersion of yttria particles

29. screw
shoulder
termination

30. 2D Mixing Animation
Colegrove & Shercliff, 2002

31. Microstructure & Performance of Joints in Superalloys