Abstract
Mo fiber reinforced NiAl in-situ composites with a nominal composition Ni-43.8Al-9.5Mo (at.%) were produced by specially controlled directional solidification (DS) using a laboratory-scale Bridgman furnace equipped with a liquid metal cooling (LMC) device. In these composites, single crystalline Mo fibers were precipitated out through eutectic reaction and aligned parallel to the growth direction of the ingot. Mechanical properties, i.e. the creep resistance at high temperatures (HT, between 900 °C and 1200 °C) and the fracture toughness at room temperature (RT) of in-situ NiAl-Mo composites, were characterized by tensile creep (along the growth direction) and flexure (four-point bending, vertical to the growth direction) tests, respectively. In the current study, a steady creep rate of 10-6s-1 at 1100 °C under an initial applied tensile stress of 150MPa was measured. The flexure tests sustained a fracture toughness of 14.5 MPa·m1/2at room temperature. Compared to binary NiAl and other NiAl alloys, these properties showed a remarkably improvement in creep resistance at HT and fracture toughness at RT that makes this composite a potential candidate material for structural application at the temperatures above 1000 °C. The mechanisms responsible for the improvement of the mechanical properties in NiAl-Mo in-situ composites were discussed based on the investigation results.
Similar content being viewed by others
References
S. M. Joslin, Ph.D. Thesis, University of Tennessee, Knoxville, TN (1995).
A. Misra, Z.L. Wu, M.T. Kush, and R. Gibala, Philos. Mag. A, 78, 533 (1998).
F.E. Heredia, M.Y. He, G.E. Lucas, A.G. Evans, H.E. Dève and D. Konitzer, Acta Metall. Mater., 41, 505 (1993).
H. Bei and E.P. George, Acta Mater, 53, 69 (2005).
W.F. Brown and J.E. Srawley, ASTM special Publication No.410, ASTM, 13 (1966).
L. Hu, W. Hu, G. Gottstein, S. Bogner, S. Hollad and A. Bührig-Polaczek, Mater. Sci, Eng. 539, 211 (2012).
A. Misra and R. Gibala, Intermetallics, 8, 1025 (2000).
A.K. Mukherjee, J.E. Bird and J.E. Dorn, Trans. ASM., 62, 155 (1964).
R.D. Noebe, R.R. Bowman and M.V. Nathal, Int. Mater. Rev., 38, 192 (1993).
R.Farraro and Rex. B. McLellan, Metall. Trans., 8, 1563(1977).
W. Ren, J. Guo, G. Li and J. Wu, Mater. T. JIM, 45 1731 (2004).
M. V. Nathal and L. J. Ebert, Metall. Trans., 16A, 427 (l985).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Zhang, G., Hu, L., Hu, W. et al. Mechanical properties of NiAl-Mo composites produced by specially controlled directional solidification. MRS Online Proceedings Library 1516, 255–260 (2013). https://doi.org/10.1557/opl.2012.1564
Published:
Issue Date:
DOI: https://doi.org/10.1557/opl.2012.1564