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Characteristics of nanophase TiAl produced by inert gas condensation

  • H. Chang (a1), C.J. Altstetter (a1) and R.S. Averback (a1)

Nanophase TiAl, with grain sizes in the range of 10–20 nm, was synthesized by magnetron sputtering in an inert gas atmosphere and consolidated, in situ, under vacuum. The properties of the powders and sintered compacts were studied by transmission electron microscopy, scanning electron microscopy, calorimetry, Rutherford backscattering, and x-ray diffraction. Samples compacted at 1.0 GPa at room temperature had a large fraction of amorphous phase, while samples compacted at the same pressure and 250 °C were predominantly the equilibrium γ phase. An enthalpy change of 22 kJ/g-atom was measured during a DSC scan over the temperature range 125–450 °C, which is approximately the range over which crystallization occurs. Nearly full density could be achieved by sintering at 450 °C without significant, concomitant grain growth. The Vickers microhardness of these samples at room temperature and at −30 °C revealed an inverse Hall–Petch relationship at small grain sizes, 10–30 nm, and the usual Hall–Petch behavior at larger grain sizes. A small component of indentation creep was also observed. The maximum hardness is 4 times larger than that of a cast TiAl specimen of the same composition. The Vickers hardness was also observed to decrease rapidly with temperature above 200 °C.

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1Lipsitt H. A., in High-Temperature Ordered Intermetallic Alloys, edited by Koch C. C., Liu C. T., and Stoloff N. S. (Mater. Res. Soc. Symp. Proc. 39, Pittsburgh, PA, 1985), p. 351.
2Aoki K. and Izumi O., J. Jpn. Inst. Met. 43, 358 (1979).
3Liu T. and Inouye H., Metall. Trans. A 10A, 1515 (1979).
4Brindley P. K., in High-Temperature Ordered Intermetallic Alloys II, edited by Stoloff N.S., Koch C.C., Liu C.T., and Izumi O. (Mater. Res. Soc. Symp. Proc. 81, Pittsburgh, PA, 1987), p. 419.
5Schulson E.M., Res. Mech. Lett. 1, 111 (1981).
6Inoue A., Masumoto T., and Tomioka H., J. Mater. Sci. 19, 3097 (1984).
7See, e.g., Granqvist C. G. and Buhrman R. A., J. Appl. Phys. 47, 2220 (1976).
8Sherby O. D. and Ruano O. A., in Superplastic Forming of Structural Alloys, edited by Paton N. E. and Hamilton C. H. (TMSAIME, Warrendale, PA, 1982), p. 241.
9Brook R. J., Proc. Brit. Ceram. Soc. 32, 7 (1982).
10Birringer R. and Gleiter H., Advances in Materials Science and Engineering, edited by Cahn R. W. (Pergamon Press, New York, 1988), p. 339.
11Froes F.H. and Suryanarayana C., J. Metals 40, 12 (1989).
12Chang H., Hofler H. J., Altstetter C. J., and Averback R. S., Scripta Metall et Mater. 25, 1161 (1991).
13Birringer R., Gleiter H., Klein H. P., and Marquart P., Phys. Lett. 102A, 365 (1984).
14Chow G. M., Chien C. L., and Edelstein A. S., J. Mater. Res. 6, 8 (1991).
15Cullity B.D., Elements of X-ray Diffraction, 2nd ed. (Addison-Wesley Publishing Co. Inc., Reading, MA, 1984), p. 102.
16Binary Alloy Phase Diagrams, 2nd ed., edited by Massalski T. B. (ASM, Metals Park, OH, 1990), Vol. 1, p. 225.
17Averback R.S., Hahn H., Hofler H.J., and Logas J.C., Appl. Phys. Lett. 57, 1745 (1990).
18Metals Reference Book, 5th ed., edited by Smithells C. J. (Butterworths & Co. Ltd., Industrial Estate, Chichester, 1976), p. 193.
19CRC Handbook of Chemistry and Physics, 62nd ed., edited by Weast R. C. (CRC Press Inc., Boca Raton, FL, 1983), p. B250.
20Miedema A. R., Boer F. R. De, and Boom R., CALPHAD 1, 341 (1977).
21Rupp J. and Birringer R., Phys. Rev. B 36, 7888 (1987).
22Jang J. S. C. and Koch C. C., J. Mater. Res. 5, 498 (1990).
23Hellstern E., Fecht H. J., Fu Z., and Johnson W. L., J. Appl. Phys. 65, 305 (1989).
24Reed-Hill R. E. and Abbaschian R., Physical Metallurgy Principles, 3rd ed. (PWS-Kent Publishing Co., Boston, MA, 1992), p. 259.
25Hancock G.F., Phys. Status Solidi A7, 535 (1971).
26Shewmon P. G., Transformations in Metals (McGraw-Hill, Inc., New York, 1969), p. 63.
27Chokski A. H., Rosen A., Karch J., and Gleiter H., Scripta Metall. 23, 1679 (1989).
28Lu K., Wei W.D., and Wang J.T., Scripta Met. et Mater. 24, 2319 (1990).
29Nieman G. W., Weertman J. R., and Siegel R. W., J. Mater. Res. 6, 1012 (1991).
30Gifkins R. C., in Superplastic Forming of Structural Alloys, edited by Paton N. E. and Hamilton C. H. (TMS-AIME, Warrendale, PA, 1982), p. 3.
31Coble R.L., J. Appl. Phys. 34, 1679 (1963).
32Gleiter H., Prog. Mater. Sci. 33, 298 (1989).
33Li W. B., Henshall J. L., Hooper R. M., and Easterling K. E., Acta Metall. 39, 3099 (1991).
34Ashby M.F. and Verrall R.A., Acta Metall. 21, 149 (1973).
35Kim Y.W., J. Metals 41, 24 (1989).
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Journal of Materials Research
  • ISSN: 0884-2914
  • EISSN: 2044-5326
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