Mechanical Properties and Fracture Behavior of Directionally Solidified NiAl-V Eutectic Composites
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Directional solidification of eutectic alloys has been recognized as promising technique for producing in situ composite materials exhibiting balance of properties. Therefore, an in situ NiAl-V eutectic composite has been successfully directionally solidified using Bridgman technique. The mechanical behavior of the composite including fracture resistance, microhardness, and compressive properties at room and elevated temperatures was investigated. Damage evolution and fracture characteristics were also discussed. The obtained results indicate that the NiAl-V eutectic retains high yield strength up to 1073 K (800 °C), above which there is a rapid decrease in strength. Its yield strength is higher than that of binary NiAl and most of the NiAl-based eutectics. The exhibited fracture toughness of 28.5 MPa√m is the highest of all other NiAl-based systems investigated so far. The material exhibited brittle fracture behavior of transgranular type and all observations pointed out that the main fracture micromechanism was cleavage.
KeywordsFracture Toughness NiAl Molybdenum Disulfide Eutectic Alloy Creep Strength
Funding of the Project NECTAR (PCIG10-GA-2011-303409) by the Marie Curie Actions Grant FP7-PEOPLE-2011-CIG program is gratefully acknowledged. SM acknowledges the Ramon y Cajal fellowships from the Spanish Ministry of Economy and Competitiveness. The financial support from the São Paulo State Research Foundation (FAPESP, Brazil) is acknowledged.
- 3.A. Misra and R. Gibala: Metall Mater. Trans. A, 1997, Vol. 28A, pp. 795–807.Google Scholar
- 5.G. Frommeyer, R. Rosenkranz, C. Ludecke: Zeit. Metallkd., 1991, Vol. 81, pp. 307–13.Google Scholar
- 22.J.D. Hunt, K.A. Jackson, Trans. Met. Soc. AIME, 1966, Vol. 236, pp. 843–52.Google Scholar
- 23.J.D. Hunt, J.P. Chilton, J. Inst. Met., 1962, Vol. 91, pp. 338–45.Google Scholar
- 24.R. Darolia, J. Met., 1991, Vol.43, pp.44–49.Google Scholar
- 25.J.L. Walter and H.E. Cline: Metall. Trans., 1970, vol. 1, pp. 1221–29.Google Scholar
- 26.G. Frommeyer and R. Rablbauer, MRS Proc., 2002, vol. 753, BB4.6.Google Scholar
- 28.P.R. Subramanian, M.G. Mendiratta, D.B. Miracle, and D.M. Dimiduk: in MRS Symposium on Intermetallic Matrix Composites II, 1990, vol. 194, pp. 147–54.Google Scholar
- 29.Annual Book of ASTM Standards: “Standard Test Method for Plane-Strain Fracture Toughness of Metallic Materials”: E-399-90, ASTM, Philadelphia, PA, 1991, vol. 03.01, p. 485.Google Scholar
- 30.R.W. Hertzberg: Deformation and Fracture Mechanics of Engineering Solids, 4th ed. New York: Wiley, 1996, pp. 164-201.Google Scholar