Skip to main content
Log in

Microstructures of LENS™ Deposited Nb-Si Alloys

  • Published:
MRS Online Proceedings Library Aims and scope

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.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. M.R. Jackson, B.P. Bewlay, R.G. Rowe, D.W. Skelly, and H.A. Lipsitt, JOM, Vol 48 No 1, 39–44, (1996).

    Article  CAS  Google Scholar 

  2. W. Hofmeister, M. Griffith, M. Ensz, J. Smugeresky, JOM, Vol 53 No 9, 30–34, (2001).

  3. K. Schwendner, R. Banerjee, P. Collins, C. Brice and H. Fraser, Scripta Materialia A, Vol. 45 No. 10, 1123–1129 (2001).

    Article  CAS  Google Scholar 

  4. B. P. Bwelay and M. R. Jackson and H. A. Lipsitt, J. Phase Equilibria, Vol. 18, 264 (1997)

    Article  Google Scholar 

  5. P. R. Subramanian, M. G. Mendiratta and D. M. Dimiduk, High Temperature Silicides and Refractory Alloys, Mats. Res. Soc. Sym. Proc., Vol. 322, 491 (1994).

    Article  CAS  Google Scholar 

  6. J.C. Zhao, M.R. Jackson and L.A. Peluso, Mat Sci and Eng. A, 372, 21–27, (2003)

    Article  Google Scholar 

Download references

Acknowledgements

Financial support for this work has been provided by the NASA URETI on Aeropropulsion and Power Technology under subgrant number E-16-V14-G1. The authors would like to thank Dr. R. D. Noebe of NASA Glenn Research Center for performing the high temperature heat treatments.

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Dehoff, R.R., Sarosi, P.M., Collins, P.C. et al. Microstructures of LENS™ Deposited Nb-Si Alloys. MRS Online Proceedings Library 842, 108–113 (2004). https://doi.org/10.1557/PROC-842-S1.11

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1557/PROC-842-S1.11

Navigation