The Theoretical Analysis of a Dynamic Softening in the Sintered Materials

O. P. Gaponova, T. P. Нovorun

Sumy State University, 2 Rymsky-Korsakov Str., UA-40007 Sumy, Ukraine

Received: 02.03.2015; final version - 13.05.2015. Download: PDF

The theoretical analysis of the kinetics of softening processes, which take place in the powder porous body during the deformation at the elevated temperatures, is carried out. The constitutive equations connecting the deformation parameters with parameters of structure formation, which characterize the dynamical softening processes during the deformation process, are obtained. The linear dependences of both the axial-stress logarithm and the accumulated deformation of solid phase as the functions of inverse temperature are established. The estimation of the activation energy of dynamical softening at uniaxial compression is carried out. As determined, the dynamical recovery and polygonization are the softening mechanisms at low deformation temperatures, while dynamical recrystallization has an effect at the elevated temperatures. Porosity decreases the activation energy of dynamical softening.

Key words: dynamical softening, uniaxial compression, axial stress, accumulated deformation, activation energy, elevated temperature, powder porous body.



PACS: 62.20.F-, 62.25.Mn, 81.05.Rm, 81.20.Ev, 81.40.Lm, 81.40.Vw, 83.10.Gr

Citation: O. P. Gaponova and T. P. Нovorun, The Theoretical Analysis of a Dynamic Softening in the Sintered Materials, Metallofiz. Noveishie Tekhnol., 37, No. 8: 1113—1123 (2015) (in Ukrainian)

  1. V. V. Stolyarov, Fizika i Tekhnika Vysokikh Davleniy, 20, No. 2: 105 (2010) (in Russian).
  2. V. A. Popov, A. V. Sisanbaev, and V. N. Danilenko, Perspektivnye Materialy, 12: 109 (2011) (in Russian).
  3. V. V. Rybin, Izvestiya Vuzov. Fizika, 3: 7 (1991) (in Russian).
  4. R. Z. Valiev and I. V. Alexandrov, Nanostrukturnye Materialy, Poluchennye Intensivnoy Plasticheskoy Deformatsiey (Moscow: Logos: 2000) (in Russian).
  5. E. I. Poliak and J. J. Jones, ISIJ International, 43, No. 5: 684 (2003). Crossref
  6. L. A. Ryabicheva, Izvestiya Vuzov. Chernaya Metallurgiya, 7: 26 (1998) (in Russian).
  7. L. A. Ryabicheva, Poelementnoe Upravlenie Strukturoobrazovaniem v Tekhnologicheskikh Protsessakh Goryachey Shtampovki (Lugansk: Izd. VUGU: 1996) (in Russian).
  8. F. Bardi, M. Cabibbo, E. Evangelista et al., Mater. Sci. Eng. A, 339, Nos. 1–2: 43 (2003). Crossref
  9. G. Zouhar, Neue Hütte, 7: 418 (1974).
  10. V. M. Leshchynski and L. A. Ryabicheva, Metallovedenie i Termoobrabotka, 1: 9 (1997) (in Russian).
  11. M. B. Stern, Poroshkovaya Metallurgiya, 6: 34 (1989) (in Russian).
  12. J. Friedel, Dislokatsii (Moscow: Mir: 1967) (Russian translation).
  13. H. G. Frost and M. F. Ashby, Karty Mekhanizmov Deformatsii (Chelyabinsk: Metallurgiya, Chelyabinskoe Otdelenie: 1989) (in Russian).
  14. O. Gaponova and L. Ryabicheva, Proc. International Conference Deformation and Fracture in Structural PM Materials DF PM 2008 (Stará Lesná, High Tatras, Slovak Republic, 2008), p. 202.
  15. L. A. Ryabicheva and O. P. Gaponova, Deformatsiya i Razrushenie Materialov, 4: 9 (2013) (in Russian).