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Metal Science and Heat Treatment

, Volume 24, Issue 7, pp 455–459 | Cite as

Effect of high-temperature vacuum annealing time on the structure and properties of titanium alloys

  • G. G. Maksimovich
  • Ya. I. Spektor
  • V. N. Fedirko
  • A. T. Pichugin
  • V. N. Moiseev
Titanium and Its Alloys
  • 55 Downloads

Conclusions

  1. 1.

    In the process of vacuum annealing at 850° under a pressure of 2.5·10−3 Pa the following changes occur in the structure of titanium alloys VT1-0, PT-7M, and OT4-1:

     
  2. a)

    Diffusion of oxygen into the metal and formation of a gas-saturated surface layer with high hardness, the thickness of which increases with the annealing time (through saturation occurs in alloy VT1-0); in this case the local concentration of oxygen in the bulk of individual grains may become so high that formation and growth of oxides are possible;

     
  3. b)

    etching of grain boundaries and the development of sublimation microrelief on the surfaces of grains, an increase in the hardness of sublimated grains, and changes in the chemical and phase composition of the surface layer due to sublimation of alloying elements.

     
  4. 2.

    With increasing annealing time the processes of gas saturation and sublimation lead to progressive damage of the surface and an increase in the thickness and effectiveness of the surface layer with changes in composition, structure, and properties, which are accompanied by lower fatigue characteristics.

     
  5. 3.

    To obtain the optimal combinations of ductile, strength, and fatigue characteristics the vacuum annealing time at high temperature for parts of titanium alloys VT1-0, PT-7M, and OT4-1 should not exceed 1 h.

     

Keywords

Fatigue Titanium Surface Layer Phase Composition Titanium Alloy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Literature cited

  1. 1.
    E. A. Borisova, I. I. Shashenkova, and R. D. Glebova, "Vacuum annealing of titanium alloys," Metalloved. Term. Obrab. Met., No. 5, 10 (1972).Google Scholar
  2. 2.
    B. A. Kolachev et al., "Structure and properties of alloys OT4 and OT4-1 after vacuum annealing," Metalloved. Term. Obrab. Met., No. 5, 6 (1972).Google Scholar
  3. 3.
    G. G. Maksimovich, Micromechanical Studies of Metals and Alloys [in Russian], Naukova Dumka, Kiev (1974).Google Scholar
  4. 4.
    V. K. Afonin, N. M. Pul'tsin, and S. A. Gorbunov, "Investigation of titanium alloys at high temperatures in vacuum," in: A New Structural Material-Titanium [in Russian], Collection of Reports at the VIII Scientific-Technical Conference on the Metallurgy, Metal Science, and Applications of Titanium, Nauka, Moscow (1972).Google Scholar
  5. 5.
    E. A. Borisova et al., "Selection of vacuum annealing conditions for titanium alloys," Metalloved. Term. Obrab. Met., No. 4, 36 (1975).Google Scholar
  6. 6.
    T. G. Garbovitskaya and L. N. Paritskaya, "Nucleation and development of oxidation centers on the surface of a metal, which are vacancy and dislocation sinks," Fiz. Met. Metalloved.,47, No. 3, 578 (1979).Google Scholar
  7. 7.
    V. I. Vodop'yanov, A. V. Gur'ev, and N. G. Shcheglov, "Mechanisms of deformation of an α titanium alloy with a brittle surface layer," in: Metal Science and Strength of Materials [in Russian], No. 4, Volgogradskii Politekhnicheskii Institut (1978), p. 16.Google Scholar

Copyright information

© Plenum Publishing Corporation 1983

Authors and Affiliations

  • G. G. Maksimovich
  • Ya. I. Spektor
  • V. N. Fedirko
  • A. T. Pichugin
  • V. N. Moiseev

There are no affiliations available

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