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Crack growth behavior in an aluminum alloy under very low stress amplitudes

Published online by Cambridge University Press:  18 July 2017

Tobias Stein
Affiliation:
Institute for Materials Engineering, University of Kassel, Kassel D-34125, Germany
Marcel Wicke
Affiliation:
Institute for Materials Engineering, University of Kassel, Kassel D-34125, Germany
Angelika Brueckner-Foit*
Affiliation:
Institute for Materials Engineering, University of Kassel, Kassel D-34125, Germany
Tina Kirsten
Affiliation:
Institute for Materials Engineering, Technical University of Dresden, Dresden D-01069, Germany
Martina Zimmermann
Affiliation:
Institute for Materials Engineering, Technical University of Dresden, Dresden D-01069, Germany
Fatih Buelbuel
Affiliation:
Institute for Materials Engineering, University of Siegen, Siegen D-57068, Germany
Hans-Juergen Christ
Affiliation:
Institute for Materials Engineering, University of Siegen, Siegen D-57068, Germany
*
a) Address all correspondence to this author. e-mail: a.brueckner-foit@uni-kassel.de
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Abstract

The near-threshold behavior of long cracks is studied in this paper using precracked flat dogbone specimens of a commercial aluminum alloy in peak-aged and overaged conditions. After introducing the initial crack in compression precracking, the crack was propagated approximately with the constant range of the stress intensity factor at values just above or below the corresponding threshold values. It was found that there were two major mechanisms which kept the crack from continuous extension. First, the crack front was pinned by primary precipitates. This effect was rather pronounced and lead to significant kinking in the crack front and ductile ridges on the fracture surface. The second mechanism was shear-controlled crack extension of very long cracks with plastic zones ahead of the crack tip, very similar to stage-I small cracks. Interaction with primary precipitates deflected the shear-controlled cracks but did not change the crack extension mode.

Type
Articles
Copyright
Copyright © Materials Research Society 2017 

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Footnotes

Contributing Editor: Mathias Göken

References

REFERENCES

Stanzl-Tschegg, S. and Mayer, H., eds.: Proceedings of the International Conference on Fatigue in the Very High Cycle Range (Institute of Meteorol and Physics, University of Agricultural Sciences, Vienna, Austria, 2001).Google Scholar
Blom, A.F., ed.: Special Session: Giga-cycle Fatigue, Proceedings of Fatigue, Vol. 5 (EMAS Ltd., West Midlands, U.K., 2002).Google Scholar
Sakai, T. and Ochi, Y., eds.: Proceedings of the 3rd International Conference on Very High-Cycle Fatigue (Society of Materials Science, Kyoto, Japan, 2004).Google Scholar
Allison, J.E., Jones, J.W., Larson, J.M., and Ritchie, R.O., eds.: Proceedings of the 4th International Conference on Very High Cycle Fatigue (TMS Publications, Ann Arbor, USA, 2007).Google Scholar
Berger, C. and Christ, H-J., eds.: Proceedings of the 5th International Conference on Very High Cycle Fatigue (DVM-Verlag, Berlin, Germany, 2011).Google Scholar
Suresh, S.: Fatigue of Materials, 2nd ed. (Cambridge University Press, Cambridge, 1998).Google Scholar
Navarro, A. and de los Rios, E.R.: Short and long fatigue crack growth: A unified model. Philos. Mag. A 57(1), 15 (1988).Google Scholar
Standard test method for measurement of fatigue crack growth rates. E 647 (ASTM International, 2003).Google Scholar
Newman, J.C. Jr.: A nonlinear fracture mechanics approach to the growth of small cracks. In Zocher, H., ed.: AGARD CP-328 (Neully-Sur-Seine, France, 1983), pp. 6.16.26.Google Scholar
Newman, J.C. Jr.: Analysis of fatigue crack growth and closure near threshold conditions. In: ASTM STP 1372 (American Society for Testing and Materials, West Conshohocken, PA); pp. 227251.Google Scholar
Forth, S.C., Newman, J.C. Jr., and Forman, R.G.: On generating fatigue crack growth thresholds. Int. J. Fatigue 25(1), 9 (2003).Google Scholar
Newman, J.C. Jr., Schneider, J., Daniel, A., and McKnight, D.: Compression pre-cracking to generate near-threshold fatigue-crack-growth rates in two aluminum alloys. Int. J. Fatigue 27(10), 1432 (2005).CrossRefGoogle Scholar
Newman, J.C. Jr. and Yamada, Y.: Compression precracking methods to generate near-threshold fatigue-crack-growth-rate data. Int. J. Fatigue 32(6), 879 (2010).CrossRefGoogle Scholar
Newman, J.C. Jr., Ruschau, J.J., and Hill, M.R.: Improved test method for very low fatigue-crack-growth-rate data. Fatigue Fract. Eng. Mater. Struct. 34(4), 270 (2011).Google Scholar
Pippan, R.: The growth of short cracks under cyclic compression. Fatigue Fract. Eng. Mater. Struct. 9(5), 319 (1987).CrossRefGoogle Scholar
Pippan, R., Plöchl, L., Klanner, F., and Stüwe, H.P.: The use of fatigue specimens precracked in compression for measuring threshold values and crack growth. ASTM J. Test. Eval. 22(2), 22 (1994).Google Scholar
Nishida, T., Pezzotti, G., Mangialardi, T., and Paolini, A.E.: Fracture mechanics evaluation of ceramics by stable crack propagation in bend bar specimens. Fract. Mech. Ceram. 11, 107 (1996).Google Scholar
Zerbst, U., Vormwald, M., Pippan, R., Gänser, H-P., Sarrazin-Baudoux, C., and Madia, M.: About the fatigue propagation threshold of metals as a design criterion—A review. Eng. Fract. Mech. 153, 190 (2016).Google Scholar
Stanzl-Tschegg, S.: Fatigue crack growth and thresholds at ultrasonic frequencies. Int. J. Fatigue 28(11), 1456 (2006).Google Scholar
Holper, B., Mayer, H., Vasudeven, A.K., and Stanzl-Tschegg, S.E.: Near threshold fatigue crack growth in aluminium alloys at low and ultrasonic frequency: Influences of specimen thickness. Int. J. Fatigue 25(5), 397 (2003).CrossRefGoogle Scholar
Steinbock, J. and Gudladt, H-J.: More insights into fatigue crack growth from experiments on steel and aluminium alloys—Thresholds. Mater. Sci. Eng., A 528(3), 1296 (2011).Google Scholar
da Fonte, M., Romeiro, F., de Freitas, M., Stanzl-Tschegg, S.E., Tschegg, E.K., and Vasudeven, A.K.: The effect of microstructure and environment on fatigue crack growth in 7049 aluminium alloy at negative stress rations. Int. J. Fatigue 25(9), 1209 (2003).Google Scholar