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Strengthening metals by narrowing grain size distributions in nickel-titanium thin films

Published online by Cambridge University Press:  19 April 2013

Xu Huang
Affiliation:
Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520
David T. Wu
Affiliation:
Department of Materials Science and Engineering, Institute of High Performance Computing, A*STAR, Singapore, 138632, Singapore
Derek Zhao
Affiliation:
Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520
Ainissa G. Ramirez*
Affiliation:
Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Grain size influences the mechanical strength of materials. In polycrystalline materials, strength increases with decreasing average grain size (for grains larger than 100 nm). This well-known Hall–Petch relationship typifies a strengthening mechanism, in which dislocation motion is impeded by grain boundaries. As grains become smaller, higher stresses are required to deform them. However, this formalism only considers the role of the “average” size of grains. Heterogeneous materials, however, have a broad “distribution” of grain sizes. Here we show that materials with narrowed grain size distributions have mechanical properties that differ from Hall–Petch predictions. Narrower distributions show increased strength, as their homogeneously sized grains yield at higher loads than the large grains in materials with broader grain size distributions. Plastic deformation depends on the coarsest grains, which yield first. These results suggest new routes for tailoring material properties.

Type
Articles
Copyright
Copyright © Materials Research Society 2013 

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References

REFERENCES

Hall, E.O.: The deformation and ageing of mild steel: III discussion of results. Proc. Phys. Soc. London, Sect. B 64, 747 (1951).CrossRefGoogle Scholar
Petch, N.J.: The cleavage strength of polycrystals. J. Iron. Steel Res. Int. 174, 25 (1953).Google Scholar
Koch, C.C., Morris, D.G., Lu, K., and Inoue, A.: Ductility of nanostructured materials. MRS Bull. 24, 54 (1999).CrossRefGoogle Scholar
Pakiela, Z., Lewandowska, M., and Kurzydlowski, K.J.: The effect of microstructural features on the mechanical properties of nanocrystalline metals, in Mechanical Properties of Nanocrystalline Materials, edited by Li, J.C.M. (Pan Stanford Publishing Pte. Ltd., Singapore, 2011), pp. 133162.Google Scholar
Bull, S.J., Sanderson, L., Moharrami, N., and Oila, A.: Effect of microstructure on hardness of submicrometre thin films and nanostructured devices. Mater. Sci. Technol. 28, 1177 (2012).CrossRefGoogle Scholar
Dieter, G.E.: Mechanical Metallurgy, 3rd ed. (McGraw-Hill, New York, 1986).Google Scholar
Kumar, K.S., Van Swygenhoven, H., and Suresh, S.: Mechanical behavior of nanocrystalline metals and alloys. Acta Mater. 51, 5743 (2003).CrossRefGoogle Scholar
Conrad, H. and Narayan, J.: On the grain size softening in nanocrystalline materials. Scr. Mater. 42, 1025 (2000).CrossRefGoogle Scholar
Kurzydlowski, K.J.: A model for the flow stress dependence on the distribution of grain size in polycrystals. Scr. Metall. Mater. 24, 879 (1990).CrossRefGoogle Scholar
Berbenni, S., Favier, V., and Berveiller, M.: Impact of the grain size distribution on the yield stress of heterogeneous materials. Int. J. Plast. 23, 114 (2007).CrossRefGoogle Scholar
Park, D.W., Sinclair, R., Lal, B.B., Malhotra, S.S., and Russak, M.A.: Grain size analysis of longitudinal thin film media. J. Appl. Phys. 87, 5687 (2000).CrossRefGoogle Scholar
Suzuki, Y.: Fabrication of shape memory alloys, in Shape Memory Materials, edited by Otsuka, K. and Wayman, C.M. (Cambridge University Press, London, 1998), pp. 133148.Google Scholar
Funakubo, H.: Shape Memory Alloys (Gordon and Breach Science Publishers, New York, 1987).Google Scholar
Lee, H.J., Ni, H., Wu, D.T., and Ramirez, A.G.: Experimental determination of kinetic parameters for crystallizing amorphous NiTi thin films. Appl. Phys. Lett. 87, 114102 (2005).CrossRefGoogle Scholar
Lee, H.J., Ni, H., Wu, D.T., and Ramirez, A.G.: Grain size estimations from the direct measurement of nucleation and growth. Appl. Phys. Lett. 87, 124102 (2005).CrossRefGoogle Scholar
Lee, H.J., Ni, H., Wu, D.T., and Ramirez, A.G.: A microstructural map of crystallized NiTi thin film derived from in situ TEM methods. Mater. Trans. 47, 527 (2006).CrossRefGoogle Scholar
Lee, H.J. and Ramirez, A.G.: Crystallization and phase transformations in amorphous NiTi thin films for microelectromechanical systems. Appl. Phys. Lett. 85, 1146 (2004).CrossRefGoogle Scholar
Lee, H.J., Huang, X., Mohanchandra, K.P., Carman, G., and Ramirez, A.G.: Effects of crystallization temperature on the stress of NiTi thin films. Scr. Mater. 60, 1133 (2009).CrossRefGoogle Scholar
Scott, M.G.: Crystallization, in Amorphous Metallic Alloys, edited by Luborsky, F.E. (Butterworths, London, 1983), pp. 144168.CrossRefGoogle Scholar
Wu, D.T.: Nucleation theory. Solid State Phys. 50, 37 (1997).CrossRefGoogle Scholar
Chu, K.T., Quek, S.S., Chee, C.Y., Chiu, J.W., and Wu, D.T.: The effect of transient nucleation on the microstructure in nucleation and growth reactions. Paper Presented at the Poster of MRS 2008 Spring Meeting, San Francisco, CA, 2008.Google Scholar
Williams, D.B. and Barry Carter, C.: Transmission Electron Microscopy: A Textbook for Materials Science (Plenum Press, New York, 1996).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).CrossRefGoogle Scholar
Yip, S.: The strongest size. Nature 391, 532 (1998).CrossRefGoogle Scholar
Adnyana, D.N.: Effect of grain size on transformation temperature in a grain refined, copper-based, shape memory alloy. Metallography 19, 187 (1986).CrossRefGoogle Scholar
Khan, A.Q., Brabers, M., and Delaey, L.: The Hall-Petch relationship in copper-based martensites. Mater. Sci. Eng. 15, 263 (1974).CrossRefGoogle Scholar
Sawaguchi, T., Sato, M., and Ishida, A.: Grain size effect on shape memory behavior of Ti35.0Ni49.7Zr15.4 thin films. Metall. Mater. Trans. A 35, 111 (2004).CrossRefGoogle Scholar
Sure, G.N. and Brown, L.C.: The mechanical properties of grain refined β-CuAlNi strain-memory alloys. Metall. Trans. A. 15, 1613 (1984).CrossRefGoogle Scholar
Wu, J.X., Bohong, J.A., and Hsu, T.Y.: Influence of grain size and ordering degree of the parent phase on Ms in a CuZnAl alloy containing boron. Acta Metall. 36, 1521 (1988).Google Scholar
Otsuka, K. and Wayman, C.M.: Mechanism of shape memory effect and superelasticity, in Shape Memory Materials, edited by Otsuka, K. and Wayman, C.M. (Cambridge University Press, New York, 1998), pp. 2749.Google Scholar
Hornbogen, E.: The effect of variables on martensitic transformation temperatures. Acta Metall. 33, 595 (1985).CrossRefGoogle Scholar
Miyazaki, S., Igo, Y., and Otsuka, K.: Effect of thermal cycling on the transformation temperature of TiNi alloys. Acta Metall. 34, 2045 (1986).CrossRefGoogle Scholar