Skip to main content Accessibility help
×
Home

Microstructures of LENS™ Deposited Nb-Si Alloys

  • Ryan R. Dehoff (a1), Peter M. Sarosi (a1), Peter C. Collins (a1), Hamish L. Fraser (a1) and Michael J. Mills (a1)...

Abstract

Nb-Si “in-situ” metal matrix composites consist of Nb3Si and Nb5Si3 intermetallic phases in a body centered cubic Nb solid solution, and show promising potential for elevated temperature structural applications. Cr and Ti have been shown to increase the oxidation resistance and metal loss rate at elevated temperatures compared to the binary Nb-Si system. In this study, the LENS™ (Laser Engineered Net Shaping) process is being implemented to construct the Nb-Ti-Cr-Si alloy system from elemental powder blends. Fast cooling rates associated with LENS™ processing yield a reduction in microstructural scale over conventional alloy processes such as directional solidification. Other advantages of LENS™ processing include the ability to produce near net shaped components with graded compositions as well as a more uniform microstructure resulting from the negative enthalpy of mixing associated with the silicide phases. Processing parameters can also be varied, resulting in distinct microstructural differences. Deposits were made with varying compositions of Nb, Ti, Cr and Si. The as-deposited as well as heat treated microstructures were examined using SEM and TEM techniques. The influence of composition and subsequent heat treatment on microstructure will be discussed.

Copyright

References

Hide All
1. Jackson, M.R., Bewlay, B.P., Rowe, R.G., Skelly, D.W., and Lipsitt, H.A., JOM, Vol 48 No 1, 3944, (1996).
2. Hofmeister, W., Griffith, M., Ensz, M., Smugeresky, J., JOM, Vol 53 No 9, 30–34, (2001).
3. Schwendner, K., Banerjee, R., Collins, P., Brice, C. and Fraser, H., Scripta Materialia A, Vol. 45 No. 10, 11231129 (2001).
4. Bwelay, B. P. and Jackson, M. R. and Lipsitt, H. A., J. Phase Equilibria, Vol. 18, 264 (1997)
5. Subramanian, P. R., Mendiratta, M. G. and Dimiduk, D. M., High Temperature Silicides and Refractory Alloys, Mats. Res. Soc. Sym. Proc., Vol. 322, 491 (1994).
6. Zhao, J.C., Jackson, M.R. and Peluso, L.A., Mat Sci and Eng. A, 372, 2127, (2003)

Microstructures of LENS™ Deposited Nb-Si Alloys

  • Ryan R. Dehoff (a1), Peter M. Sarosi (a1), Peter C. Collins (a1), Hamish L. Fraser (a1) and Michael J. Mills (a1)...

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed