Effect of Mo Addition on Microstructure and Properties of Nb/Nb5Si3 In-Situ Composite


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Nb/Nb5Si3 in-situ composites are very attractive structural materials for these materials perform a good balance in mechanical properties, including a high strength at high temperature (>1373K) and reasonably high fracture toughness at room temperature. Metastable phase Nb3Si plays an important role in the properties of Nb/Nb5Si3 composites by affecting microstructure and volume fracture of ductile phase. In this paper, Nb-10Si-xMo and Nb-18Si-xMo (x=0,5,15) are prepared by arc melting and annealed at 1473K for 100h. Single edge-notched bending (SENB) test was used to study the fracture toughness of Nb-Si-Mo alloys. The stability of metastable phase is analyzed by XRD. The room temperature fracture toughness of Nb-10Si is 10.47MPa(m)1/2 and higher than that of binary Nb-18Si alloys at near-eutectic compositions. The addition of Mo improves the fracture toughness of as cast Nb-Si alloys from 4.1 MPa(m)1/2 to 9.9MPa(m)1/2 at near-eutectic compositions and decreases it from 10.47 MPa(m)1/2 to 8.8MPa(m)1/2 at hypoeutectic compositions.



Materials Science Forum (Volumes 449-452)

Edited by:

S.-G. Kang and T. Kobayashi




W. Li et al., "Effect of Mo Addition on Microstructure and Properties of Nb/Nb5Si3 In-Situ Composite", Materials Science Forum, Vols. 449-452, pp. 753-756, 2004

Online since:

March 2004




[1] L. A. Edward: JOM, Vol. 39, (1987), p.22.

[2] M. G. Mendiratta and D. M. Dimiduk: Scripta Metallurgica et Materialia, Vol. 25 (1991), p.237.

[3] M. G. Mendiratta and D. M. Dimiduk: Metall. Trans. A, Vol. 24A (1993), p.501.

[4] M. R. Jackson, B. P. Bewlay and R. G. Rowe: JOM, Vol. 48 (1996), p.39.

[5] B. P. Bewlay, M. R. Jackson and H. A. Lipsitt: Metall. Mater. Trans., Vol. 27A (1996), p.3801.

[6] W. -Y. Kim, H. Tanaka and S. Hanada: Intermetallics, Vol. 10 (2002), p.625.

[7] W. -Y. Kim, H. Tanaka and A. Kasama: Intermetallics, Vol. 9 (2001), p.521.

[8] D. M. Shah, D. L. Anton and D. P. Pope: Mater. Sci. Eng., Vol. A192/193 (1995), p.658.