Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-28T00:56:40.244Z Has data issue: false hasContentIssue false

Micromechanical study on the deformation behavior of directionally solidified NiAl–Cr eutectic composites

Published online by Cambridge University Press:  14 February 2017

Amritesh Kumar
Affiliation:
Institute for Applied Materials, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen 76344, Germany
Charlotte Ensslen
Affiliation:
Institute for Applied Materials, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen 76344, Germany
Antje Krüger
Affiliation:
Institute for Applied Materials, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen 76344, Germany
Michael Klimenkov
Affiliation:
Institute for Applied Materials, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen 76344, Germany
Oliver Kraft
Affiliation:
Institute for Applied Materials, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen 76344, Germany
Ruth Schwaiger*
Affiliation:
Institute for Applied Materials, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen 76344, Germany
*
a)Address all correspondence to this author. e-mail: ruth.schwaiger@kit.edu
Get access

Abstract

The effect of Cr fibers on the deformation of directionally solidified NiAl–Cr eutectics, prepared at three different solidification speeds affecting the fiber diameter and fiber spacing, was studied at varying length scales using different micromechanical testing techniques. In situ tensile tests in a scanning electron microscope of individual Cr fibers showed high strength accompanied by ductile behavior. Comparative microcompression tests on single-phase NiAl pillars and NiAl pillars containing a single fiber showed that the pillars with the single fiber were marginally weaker than the single-phase pillars for similar pillar diameters. Composite pillars with multiple fibers exhibited an increase of 0.2% offset strength values with increasing solidification speed. Transmission electron microscopy of the composite pillars containing a single fiber after deformation revealed significant dislocation activity both in the fiber and the matrix. It is argued that the interface between the fiber and matrix acts as dislocation source promoting plastic deformation of the brittle NiAl matrix.

Type
Articles
Copyright
Copyright © Materials Research Society 2017 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

Contributing Editor: Yang-T. Cheng

References

REFERENCES

Darolia, R.: NiAl alloys for high temperature structural applications. JOM 43, 44 (1991).Google Scholar
Miracle, D.B.: The physical and mechanical properties of NiAl. Acta Metall. Mater. 41, 649 (1993).Google Scholar
Liu, C.T. and Horton, J.A. Jr.: Effect of refractory alloying additions on mechanical properties of near-stoichiometric NiAl. Mater. Sci. Eng., A 192–193, 170 (1995).Google Scholar
Frommeyer, G. and Rablbauer, R.: High temperature materials based on the intermetallic compound NiAl reinforced by refractory metals for advanced energy conversion technologies. Steel Res. Int. 79, 507 (2008).Google Scholar
Yang, J-M.: The mechanical behavior of in-situ NiAl-refractory metal composites. JOM 49, 40 (1997).Google Scholar
Bei, H. and George, E.P.: Microstructures and mechanical properties of a directionally solidified NiAl–Mo eutectic alloy. Acta Mater. 53, 69 (2005).Google Scholar
Chen, X.F., Johnson, D.R., Noebe, R.D., and Oliver, B.F.: Deformation and fracture of a directionally solidified NiAl–28Cr–6Mo eutectic alloy. J. Mater. Res. 10, 1159 (1995).Google Scholar
Qi, Y.H., Ma, S.N., and Guo, J.T.: Microstructure, and high temperature mechanical property of directionally solidified NiAl–Cr(Mo)–W/Nb alloy. Adv. Mater. Res. 299–300, 167 (2011).CrossRefGoogle Scholar
Cline, H.E. and Walter, J.L.: The effect of alloy additions on the rod-plate transition in the eutectic NiAl–Cr. Metall. Trans. 1, 2907 (1970).Google Scholar
Walter, J.L. and Cline, H.E.: The effect of solidification rate on structure and high-temperature strength of the eutectic NiAl–Cr. Metall. Trans. 1, 1221 (1970).CrossRefGoogle Scholar
Hu, L., Hu, W., Gottstein, G., Bogner, S., Hollad, S., and Bührig-Polaczek, A.: Investigation into microstructure and mechanical properties of NiAl–Mo composites produced by directional solidification. Mater. Sci. Eng., A 539, 211 (2012).Google Scholar
Bei, H., Shim, S., Pharr, G.M., and George, E.P.: Effects of pre-strain on the compressive stress-strain response of Mo-alloy single-crystal micropillars. Acta Mater. 56, 4762 (2008).Google Scholar
Phani, P.S., Johanns, K.E., Duscher, G., Gali, A., George, E.P., and Pharr, G.M.: Scanning transmission electron microscope observations of defects in as-grown and pre-strained Mo alloy fibers. Acta Mater. 59, 2172 (2011).Google Scholar
Johanns, K.E., Sedlmayr, A., Sudharshan Phani, P., Mönig, R., Kraft, O., George, E.P., and Pharr, G.M.: In-situ tensile testing of single-crystal molybdenum-alloy fibers with various dislocation densities in a scanning electron microscope. J. Mater. Res. 27, 508 (2012).Google Scholar
Oliver, W.C. and Pharr, G.M.: Measurement of hardness and elastic modulus by instrumented indentation: Advances in understanding and refinements to methodology. J. Mater. Res. 19, 3 (2004).CrossRefGoogle Scholar
Oliver, W.C. and Pharr, G.M.: An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. J. Mater. Res. 7, 1564 (1992).Google Scholar
Greer, J.R., Oliver, W.C., and Nix, W.D.: Size dependence of mechanical properties of gold at the micron scale in the absence of strain gradients. Acta Mater. 53, 1821 (2005).Google Scholar
Gianola, D.S., Sedlmayr, A., Mönig, R., Volkert, C.A., Major, R.C., Cyrankowski, E., Asif, S.A.S., Warren, O.L., and Kraft, O.: In situ nanomechanical testing in focused ion beam and scanning electron microscopes. Rev. Sci. Instrum. 82, 063901 (2011).Google Scholar
Boles, S.T., Sedlmayr, A., Kraft, O., and Mönig, R.: In situ cycling and mechanical testing of silicon nanowire anodes for lithium-ion battery applications. Appl. Phys. Lett. 100, 243901 (2012).Google Scholar
Ensslen, C., Brandl, C., Richter, G., Schwaiger, R., and Kraft, O.: Notch insensitive strength and ductility in gold nanowires. Acta Mater. 108, 317 (2016).Google Scholar
Eberl, C., Gianola, D.S., and Thompson, R.: MATLAB file exchange. http://www.mathworks.com/matlabcentral/fileexchange/12413 (2006).Google Scholar
Frommeyer, G., Rablbauer, R., and Schäfer, H.J.: Elastic properties of B2-ordered NiAl and NiAl-X (Cr, Mo, W) alloys. Intermetallics 18, 299 (2010).Google Scholar
Kraft, O., Gruber, P.A., Mönig, R., and Weygand, D.: Plasticity in confined dimensions. Annu. Rev. Mater. Res. 40, 293 (2010).Google Scholar
Senger, J., Weygand, D., Motz, C., Gumbsch, P., and Kraft, O.: Aspect ratio and stochastic effects in the plasticity of uniformly loaded micrometer-sized specimens. Acta Mater. 59, 2937 (2011).Google Scholar
Mompiou, F., Legros, M., Sedlmayr, A., Gianola, D.S., Caillard, D., and Kraft, O.: Source-based strengthening of sub-micrometer Al fibers. Acta Mater. 60, 977 (2012).Google Scholar
Chisholm, C., Bei, H., Lowry, M.B., Oh, J., Syed Asif, S.A., Warren, O.L., Shan, Z.W., George, E.P., and Minor, A.M.: Dislocation starvation and exhaustion hardening in Mo alloy nanofibers. Acta Mater. 60, 2258 (2012).Google Scholar
Fei, H., Abraham, A., Chawla, N., and Jiang, H.: Evaluation of micro-pillar compression tests for accurate determination of elastic-plastic constitutive relations. J. Appl. Mech. 79, 061011 (2012).Google Scholar
Schwaiger, R., Weber, M., Moser, B., Gumbsch, P., and Kraft, O.: Mechanical assessment of ultrafine-grained nickel by microcompression experiment and finite element simulation. J. Mater. Res. 27, 266 (2011).Google Scholar
Kiener, D., Motz, C., Rester, M., Jenko, M., and Dehm, G.: FIB damage of Cu and possible consequences for miniaturized mechanical tests. Mater. Sci. Eng., A 459(1), 262 (2007).Google Scholar
Duesbery, M.S. and Vitek, V.: Plastic anisotropy in b.c.c. transition metals. Acta Mater. 46, 1481 (1998).Google Scholar
Cline, H.E., Walter, J.L., Koch, E.F., and Osika, L.M.: The variation of interface dislocation networks with lattice mismatch in eutectic alloys. Acta Metall. 19, 405 (1971).Google Scholar
Walter, J.L., Cline, H.E., and Koch, E.F.: Interface dislocations in directionally solidified NiAl–Cr eutectic. Trans. Metall. Soc. AIME 245, 2073 (1969).Google Scholar
Misra, A. and Gibala, R.: Plasticity in multiphase intermetallics. Intermetallics 8, 1025 (2000).Google Scholar
Kwon, J., Bowers, M.L., Brandes, M.C., McCreary, V., Robertson, I.M., Phani, P.S., Bei, H., Gao, Y.F., Pharr, G.M., George, E.P., and Mills, M.J.: Characterization of dislocation structures and deformation mechanisms in as-grown and deformed directionally solidified NiAl–Mo composites. Acta Mater. 89, 315 (2015).Google Scholar
Noebe, R.D., Misra, A., and Gibala, R.: Plastic flow and fracture of B2 NiAl-based intermetallic alloys containing a ductile second phase. ISIJ Int. 31, 1172 (1991).Google Scholar
Bei, H., Gao, Y.F., Shim, S., George, E.P., and Pharr, G.M.: Strength differences arising from homogeneous versus heterogeneous dislocation nucleation. Phys. Rev. B: Condens. Matter Mater. Phys. 77, 25 (2008).Google Scholar
Battaile, C.C., Boyce, B.L., Weinberger, C.R., Prasad, S.V., Michael, J.R., and Clark, B.G.: The hardness and strength of metal tribofilms: An apparent contradiction between nanoindentation and pillar compression. Acta Mater. 60, 17121720 (2012).CrossRefGoogle Scholar