Time-Resolved Flow Stress Behavior of Structural Materials at Low Temperatures

  • B. Obst
  • A. Nyilas
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 44)


During low-temperature testing of metals and alloys, the load developed in a specimen is measured in-place with a time resolution of up to 5μs. A load drop resulting from a rapid excessive event of plastic relaxation (“plastic instability”) emerges as a coupled two-stage process: A linear drop at very high rate at macroscopic level is followed by a quasi-exponential drop at much smaller rate. The surface temperature of the specimen measured with a thermocouple during loading shows no significant rise until the load has started to fall. These experimental findings are discussed in terms of dislocation motion controlled by viscous and thermally activated mechanisms, respectively.


Plastic Instability Plastic Relaxation Constant Crosshead Speed Maximum Sampling Rate Solid State Data 


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  1. 1.
    H. Neuhäuser, Problems in Solid Solution Hardening, Physica Scripta T49: 412 (1993)CrossRefGoogle Scholar
  2. 2.
    Y. Brechet and F. Louchet, Plastic instabilities and their relation to fracture, Materials Science and Engineering A 164: 35 (1993).CrossRefGoogle Scholar
  3. 3.
    M. Zaiser, Spatio - Temporal Aspects of Low Temperature Thermomechanical Instabilities: A Model based on Dislocation Dynamics, Appl. Phys. A 57: 143 (1993).Google Scholar
  4. 4.
    M.A. Lebyodkin and V.S. Bobrov, Role of Dynamical Processes at Discontinuous Deformation of Aluminium, Solid State Phenomena 35 – 36: 411 (1994).Google Scholar
  5. 5.
    M.Zaiser, Stability Criteria for Plastic Deformation at Low-Temperatures, Scr.Metall.Mater. 32: 1261 (1995)CrossRefGoogle Scholar
  6. 6.
    H.E. Dève and R.J. Asaro, The Development of Plastic Failure Modes in Crystalline Materials: Shear Bands in Fcc Polycrystals, Metallurgical Transactions A 20 A: 579 (1989).Google Scholar
  7. 7.
    P. Ogata and K. Ishikawa, Discontinuous deformation of austenitic stainless steels in superfluid helium, Journal of Materials Science Letters 4: 1079 (1985).CrossRefGoogle Scholar
  8. 8.
    B. Obst and W. Bauriedl, The Instability of Plastic Flow at Low Temperatures - An Explanation from a New Point of View, Advances in Cryogenic Engineering Materials 31: 275 (1988).Google Scholar
  9. 9.
    A. Seeger and W. Frank, Structure Formation by Dissipative Processes in Crystals with High Defect Densities, Solid State Data, Part B, B3–B4: 125 (1988). 6.Google Scholar
  10. 10.
    A.M. Dolgin and V.D. Natsik, Criteria of Instability and Kinetics of Jumps under Unstable Low Temperature Plastic Flow, Acta Univ. Carolin.-Mat. et Phys. (Prague) 32: 77 (1991).Google Scholar
  11. 11.
    R.B. Schwarz and J.W. Mitchell, Dynamic dislocation phenomena in single crystals of Cu - 10.5 at%Al alloys at 4.2 K, Phys. Rev. B 9: 3292 (1974).ADSCrossRefGoogle Scholar
  12. 12.
    A.M. Dolgin and V.Z. Bengus, Kinetics of High-Velocity Processes of Low-Temperature Jump-Like Deformation of Niobium, phys. stat. sol. (a) 94: 529 (1986).ADSGoogle Scholar
  13. 13.
    T.H. Blewitt, R.R. Coltmann, and J.K. Redman, Low-Temperature Deformation of Copper Single Crystals, in: Dislocations and Mechanical Properties of Crystals, J.C. Fisher et al., eds._ John Wiley & Sons, New York (1957), p. 179.Google Scholar
  14. 14.
    O. Vöhringer, Einsatzspannung für mechanische Zwillingsbildung bei a-Kupferlegierungen, Z. Metallkde 67: 518 (1976).Google Scholar
  15. 15.
    B. Obst and A. Nyilas, Experimental evidence on the dislocation mechanism of serrated yielding in f.c.c. metals and alloys at low temperatures, Materials Science and Engineering A 137: 141 (1991).Google Scholar
  16. 16.
    A. Nyilas, B. Obst and H. Nakajima, Tensile Properties, Fracture, and Crack Growth of a Nitrogen Strengthened New Stainless Steel for Cryogenic Use, in: Proc. of 3`d Int. Conf. “High Nitrogen Steels-93”, Sept. 14–16 (1993), Kiev, Ukraine, (eds. V.G. Gavriljuk and V.M. Nadutov, Vol.II, p. 339.Google Scholar
  17. 17.
    P.A. Parkhomenko and V.V. Pustovalov, The Low-Temperature Yield Stress Anomaly in Metals and Alloys, phys. stat. sol. (a) 74: 11 (1982).ADSCrossRefGoogle Scholar
  18. 18.
    V.A. Moskalenko, V.I. Startsev, and V.N. Kovaleva, Low temperature pecularities of plastic deformation in titanium and its alloys, Cryogenics 20: 503 (1980).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • B. Obst
    • 1
  • A. Nyilas
    • 1
  1. 1.Forschungszentrum KarlsruheInstitut für Technische PhysikKarlsruheGermany

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