Добавил:
Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Module_V.doc
Скачиваний:
48
Добавлен:
11.03.2015
Размер:
3.38 Mб
Скачать
  1. Conclusions

  1. Improved testing procedures show that raising the solution annealing temperature appears to increase both the primary and steady-state creep resistance of Ti 6242Si. This beneficial effect may be derived from a combination of several sources, including the removal of such micrographic features as banding or texturing and especially the altering or refining of the α or β microstructure.

  2. Small concentrations of Ni appear to segregate uniformly into the β phase and dramatically degrade the creep properties of Ti 6242Si. The explanation for this is unclear.

  3. Small additions of Cr have little, if any, affect on the creep resistance of the alloy.

  4. The β phase, which comprises only about 10 pct of the alloy, may have a much more important role in the creep of Ti 6242Si over the small strain range examined than previously acknowledged.

Acknowledgments

The authors would like to acknowledge the financial support provided by the United States Bureau of Mines, Oregon Metallurgical Corporation (OREMENT), and the Oregon Economic Development Department through the Oregon Metals Initiative. We would also like to acknowledge the assistance of The United States Bureau of Mines for performing our press forging and of G. Buchanan at OREMENT who performed our coupon forgings. Finally, we would like to acknowledge the assistance of U. Kansal with the metallography and Professor J. Koike with the TEM in this work. Conversations with Dr. P. Bania of TIMET are also appreciated.

References

  1. S.A.E. Aerospace Material Specification 4976D, Society of Automotive Engineers, Warrendale, PA, 1988.

  2. P.J. Bania and J.A. Hall: Titanium Scence and Technology, Deutsche Gesellschaft fur Metallkunde, Oberursel, Germany, 1985, pp.2371-78.

  3. S.R. Seagle, G.S. Hall, and H.B. Bomberger: Met. Eng. Q., 1972, feb., pp. 48-54.

  4. C.C. Chen and J.E. Coyne: Titanium ’80 Science and Technology, TMS-AIME, Warrendale, PA, 1980, pp. 1197-1207.

  5. P.J. Bania, J. Hall, and L. Bidwell: Interim Technical Report, AFML Contract No. F33615-75-C-5089, 1975.

  6. S. Ankem and S.R. Seagle: Titanium Science and Technology, Deutsche Gesellschaft fur Metallkunde, Oberursel, Germany, 1985, pp. 2411-18.

  7. Quesne, C. Duong, F. Charpentier, J. Fries, and P. Lacombe: J. Less-Common Met., 1979, vol. 68, pp. 133-42.

  8. Hiatt and B. Bristow: OREMET Corp., Albany, R, private communication, 1991.

  9. Annual Book of ASTM Standards, 3.1, ASTM Testing Standard E696, Philadelphia, ASTM, PA, 1980, p. 609.

  10. C.W. Schmidt: G.E. Quality Specifications S-400B, Evandale OH, 1990, pp. 24-26.

  11. U. Kansal, M.E. Kassner, D. Hiatt, and B. Bristow: J. Eng. Mater, Perform., 1992, vol. 1, pp. 393-98.

  12. Neil Paton and M.W. Mahoney: Metall. Trans. A, 1976, vol. 7A, pp. 1685-94.

  13. W. Evans and G. Harrison: J. Mater. Sci., 1983, vol. 18, pp. 3449-55.

  14. M.E. Kassner and X. Li: Scripta Metall. Mater., 1991, vol. 25, pp. 2833-38.

  15. S.L. Semiatin and G.D. Lahoti: metal. Trans. A, 1983, 14A, pp. 743-50.

  16. O.D. Sherby and P.M. Burke: Prog. Mater. Sci., 1968, vol. 13, pp. 325-90.

  17. Metals Reference Book, C.J. Smithells and E.A. Brandes, eds., Butterworths, London, 1976, p. 879.

Соседние файлы в предмете [НЕСОРТИРОВАННОЕ]