Home New method of determining stress relaxation behavior in creep machines by controlled unloading
Article
Licensed
Unlicensed Requires Authentication

New method of determining stress relaxation behavior in creep machines by controlled unloading

  • Wolfgang Blum EMAIL logo and Falk Breutinger
Published/Copyright: January 3, 2022
Become an author with De Gruyter Brill
Author Information
International Journal of Materials Research
From the journal International Journal of Materials Research Volume 93 Issue 7

Abstract

Conventional measurement of stress relaxation in tests with constant total (elastic plus inelastic plus thermal) strain requires high resolution and excellent control of strain and is perturbed by thermal fluctuations. A new method for measuring the stress relaxation behavior is presented which avoids these experimental problems. It is based on the fact that the stress relaxation behavior is fully contained in the relation between inelastic strain rate and stress at given mechanical strain. Consequently, it should be possible to measure stress relaxation in creep machines when stepwise unloading is performed such that the inelastic strain rate can be determined at constant mechanical strain. This is confirmed by tests on the Mg-base alloy AZ91.

Abstract

Konventionelle Messung der Spannungsrelaxation in Versuchen bei konstanter totaler Dehnung (elastisch plus inelastisch plus thermisch) verlangt hohe Auflösung und exzellente Regelung der Dehnung und ist empfindlich gegenüber Temperaturschwankungen. Eine neue Methode zur Bestimmung des Spannungsrelaxationsverhaltens wird vorgestellt, die diese experimentellen Probleme vermeidet. Sie basiert darauf, dass das Spannungsrelaxationsverhalten eindeutig aus der Beziehung zwischen inelastischer Verformungsrate und Spannung bei gegebener mechanischer Dehnung folgt. Daher sollte die Spannungsrelaxation in Kriechapparaturen gemessen werden können, indem stufenweise derart entlastet wird, dass die inelastische Verformungsgeschwindigkeit bei fester mechanischer Dehnung bestimmbar ist. Dies wird durch Versuche an der Mg-Basislegierung AZ91 bestätigt.

Keywords: Stress relaxation; Creep; Mg-base alloy
Prof. Wolfgang Blum Institut fur Werkstoffwissenschaften, LS I Universität Erlangen-Nürnberg Martensstr. 5, D-91058 Erlangen, Germany Tel.: +49 9131 852 7507 Fax: +49 9131 852 7504

  1. Thanks are due to the AUDI AG for support of this work.

References

1 Hart, E.W.; Li, C.Y.; Yamada, H.; Wire, G.L., in: A.S. Argon (ed.), Constitutive Equations in Plasticity, MIT Press, Cambridge, Mass., London (1975) 149.Search in Google Scholar

2 Zhang, P.; Watzinger, B.; Blum, W.: phys. stat. sol. (a) 175 (1999) 481.10.1002/(SICI)1521-396X(199910)175:2<481::AID-PSSA481>3.0.CO;2-JSearch in Google Scholar

3 Zhang, P.; Agamennone, R.; Blum, W.; Grossmann, B.v.; Halden-wanger, H.-G., in: K.U. Kainer (ed.), Proc. Int. Symp. on Magnesium Alloys and Their Applications, Wiley-VCH, Weinheim (2000) 716.Search in Google Scholar

4 Zhang, P.; Watzinger, B.; Kong, Q.P.; Blum, W.: Key Eng. Mater. 171–174 (2000) 609.Search in Google Scholar

5 Brandes, E.A.; Brook, G.B. (eds.): Smithells Metals Reference Book, Hartnolk Ltd, Bodmin, Cornwall (1992).Search in Google Scholar

6 Frost, H.-J.; Ashby, M.F.: Deformation-Mechanism Maps, Pergamon Press, Oxford (1982).Search in Google Scholar

7 Blum, W.; Weidinger, P.; Watzinger, B.; Sedlacek, R.; Rösch, R.; Haldenwanger, H.-G.: Z. Metallkd. 88 (1997) 636.Search in Google Scholar

8 Watzinger, B.; Weidinger, P.; Breutinger, F.; Blum, W.; Rösch, R.; Lipowsky, H.; Haldenwanger, H.-G., in: B.L. Mordike, K.U. Kainer (eds.): Magnesium Alloys and Their Applications, MATINFO Werkstoff-Informationsgesellschaft, Frankfurt (1998) 259.Search in Google Scholar

9 Hausselt, J.; Blum, W.: Acta metall. 24 (1976) 1027.10.1016/0001-6160(76)90133-4Search in Google Scholar
Received: 2002-02-18
Published Online: 2022-01-03

© 2002 Carl Hanser Verlag, München

Articles in the same Issue

  1. Frontmatter
  2. Editorial
  3. Editorial
  4. Articles/Aufsätze
  5. A model for the work hardening of WC–Co “hard metals”
  6. On the dispersion strengthening mechanisms in ODS materials
  7. Effect of hydrogen on the mechanical properties of the β titanium alloy Timetal® 21S
  8. Cyclic deformation behaviour of (α + β) titanium alloys under complex mechanical and physiological loading conditions
  9. Assessment of the influence of interdendritic shrinkage cavities on the thermo-mechanical fatigue behaviour of the nickel-base superalloy MAR-M247LC
  10. Effects of static strain aging on residual stress stability and alternating bending strength of shot peened AISI 4140
  11. On the possibilities to enhance the fatigue properties of ultrafine-grained metals
  12. New method of determining stress relaxation behavior in creep machines by controlled unloading
  13. Creep of binary Ni-rich NiTi shape memory alloys and the influence of pre-creep on martensitic transformations
  14. Interaction of high-cycle fatigue with high-temperature creep in superalloy single crystals
  15. A unified description of creep in pure and dispersion-strengthened copper
  16. A new interpretation of flow-stress measurements of high-purity NiAl below room temperature
  17. A mesoscopic plasticity model accounting for spatial fluctuations of plastic strains, internal stresses and dislocation densities
  18. Behavior of X-ray peak widths in the Wilkens model of a restrictedly random distribution of dislocations
  19. Dislocation structure and crystallite size distribution in hexagonal nanomaterials from X-ray peak profile analysis
  20. Werden gewichtsoptimiert konstruierte Bauteile durch die Verwendung von Leichtmetallen wirklich leichter?*)
  21. Strain-induced martensite formation in metastable austenitic steels with varying carbon content
  22. Isothermal bainitic transformation in low alloy steels: factors limiting prediction of the resulting material’s properties
  23. Fatigue damage evolution in a particulate-reinforced metal matrix composite determined by acoustic emission and compliance method
  24. Microstructure and modification mechanisms of Si phase in as-thixoformed alloy A356
  25. Influence of size effect on microstructural changes in cyclically deformed polycrystalline nickel
  26. Self-diffusion of 71Ge and 31Si in Si –Ge alloys
  27. On localised corrosive attack, stress corrosion cracking and corrosion fatigue effects in a hardmetal cutting-tool material
  28. The internal stress during growth of SiC single crystals
  29. Notifications/Mitteilungen
  30. Personal/Personelles
  31. Books/Bücher
  32. DGM Conferences/Training
https://doi.org/10.3139/ijmr-2002-0110
Keywords for this article
Stress relaxation; Creep; Mg-base alloy

Articles in the same Issue

  1. Frontmatter
  2. Editorial
  3. Editorial
  4. Articles/Aufsätze
  5. A model for the work hardening of WC–Co “hard metals”
  6. On the dispersion strengthening mechanisms in ODS materials
  7. Effect of hydrogen on the mechanical properties of the β titanium alloy Timetal® 21S
  8. Cyclic deformation behaviour of (α + β) titanium alloys under complex mechanical and physiological loading conditions
  9. Assessment of the influence of interdendritic shrinkage cavities on the thermo-mechanical fatigue behaviour of the nickel-base superalloy MAR-M247LC
  10. Effects of static strain aging on residual stress stability and alternating bending strength of shot peened AISI 4140
  11. On the possibilities to enhance the fatigue properties of ultrafine-grained metals
  12. New method of determining stress relaxation behavior in creep machines by controlled unloading
  13. Creep of binary Ni-rich NiTi shape memory alloys and the influence of pre-creep on martensitic transformations
  14. Interaction of high-cycle fatigue with high-temperature creep in superalloy single crystals
  15. A unified description of creep in pure and dispersion-strengthened copper
  16. A new interpretation of flow-stress measurements of high-purity NiAl below room temperature
  17. A mesoscopic plasticity model accounting for spatial fluctuations of plastic strains, internal stresses and dislocation densities
  18. Behavior of X-ray peak widths in the Wilkens model of a restrictedly random distribution of dislocations
  19. Dislocation structure and crystallite size distribution in hexagonal nanomaterials from X-ray peak profile analysis
  20. Werden gewichtsoptimiert konstruierte Bauteile durch die Verwendung von Leichtmetallen wirklich leichter?*)
  21. Strain-induced martensite formation in metastable austenitic steels with varying carbon content
  22. Isothermal bainitic transformation in low alloy steels: factors limiting prediction of the resulting material’s properties
  23. Fatigue damage evolution in a particulate-reinforced metal matrix composite determined by acoustic emission and compliance method
  24. Microstructure and modification mechanisms of Si phase in as-thixoformed alloy A356
  25. Influence of size effect on microstructural changes in cyclically deformed polycrystalline nickel
  26. Self-diffusion of 71Ge and 31Si in Si –Ge alloys
  27. On localised corrosive attack, stress corrosion cracking and corrosion fatigue effects in a hardmetal cutting-tool material
  28. The internal stress during growth of SiC single crystals
  29. Notifications/Mitteilungen
  30. Personal/Personelles
  31. Books/Bücher
  32. DGM Conferences/Training
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 7.9.2025 from https://www.degruyterbrill.com/document/doi/10.3139/ijmr-2002-0110/html
Scroll to top button