Hostname: page-component-8448b6f56d-c47g7 Total loading time: 0 Render date: 2024-04-19T12:07:26.360Z Has data issue: false hasContentIssue false
  • English
  • Français

Fracture toughness evaluation of NiAl single crystals by microcantilevers—a new continuous J-integral method

Published online by Cambridge University Press:  07 November 2016

Johannes Ast ,
Benoit Merle ,
Karsten Durst  and
Mathias Göken
Johannes Ast*
Affiliation:
Department of Materials Science and Engineering, Institute I: General Materials Properties, Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen 91058, Germany
Benoit Merle
Affiliation:
Department of Materials Science and Engineering, Institute I: General Materials Properties, Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen 91058, Germany
Karsten Durst
Affiliation:
Department of Physical Metallurgy, Technical University of Darmstadt, Darmstadt 64287, Germany
Mathias Göken
Affiliation:
Department of Materials Science and Engineering, Institute I: General Materials Properties, Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen 91058, Germany
*
a) Address all correspondence to this author. e-mail: johannes.ast@empa.ch
Get access

Abstract

The fracture toughness of NiAl single crystals is evaluated with a new method based on the J-integral concept. The new technique allows the measurement of continuous crack resistance curves at the microscale by continuously recording the stiffness of the microcantilevers with a nanoindenter. The experimental procedure allows the determination of the fracture toughness directly at the onset of stable crack growth. Experiments were performed on notched microcantilevers which were prepared by focused ion beam milling from NiAl single crystals. Stoichiometric NiAl crystals and NiAl crystals containing 0.14 wt% Fe were investigated in the so-called “hard” orientation. The fracture toughness was evaluated to be 6.4 ± 0.5 MPa m1/2 for the stoichiometric sample and 7.1 ± 0.5 MPa m1/2 for the iron containing sample, indicating that the addition of iron enhances the ductility. This effect is intensified with ongoing crack propagation where the Fe-containing sample exhibits a stronger crack resistance behavior than the stoichiometric NiAl single crystal. These findings are in good agreement with macroscopic fracture toughness measurements, and validate the new micromechanical testing approach.

Keywords

NiAlfracture mechanicsJ-integralfocused ion beammicro-cantilever tests
Type
Articles
Information
Journal of Materials Research , Volume 31 , Issue 23 , 14 December 2016 , pp. 3786 - 3794
Check for updates
Copyright
Copyright © Materials Research Society 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Di Maio, D. and Roberts, S.G.: Measuring fracture toughness of coatings using focused-ion-beam-machined microbeams. J. Mater. Res. 20(2), 299 (2005).CrossRefGoogle Scholar
Schaufler, J., Schmid, C., Durst, K., and Göken, M.: Determination of the interfacial strength and fracture toughness of a-C:H coatings by in situ microcantilever bending. Thin Solid Films 522, 480 (2012).CrossRefGoogle Scholar
Matoy, K., Schönherr, H., Detzel, T., Schöberl, T., Pippan, R., Motz, C., and Dehm, G.: A comparative micro-cantilever study of the mechanical behavior of silicon based passivation films. Thin Solid Films 518(1), 247 (2009).Google Scholar
Žagar, G., Pejchal, V., Mueller, M.G., Michelet, L., and Mortensen, A.: Fracture toughness measurement in fused quartz using triangular chevron-notched micro-cantilevers. Scr. Mater. 112, 132 (2016).CrossRefGoogle Scholar
Jaya, B.N., Kirchlechner, C., and Dehm, G.: Can microscale fracture tests provide reliable fracture toughness values? A case study in silicon. J. Mater. Res. 30(5), 686 (2015).Google Scholar
Mueller, M.G., Pejchal, V., Žagar, G., Singh, A., Cantoni, M., and Mortensen, A.: Fracture toughness testing of nanocrystalline alumina and fused quartz using chevron-notched microbeams. Acta Mater. 86, 385 (2015).Google Scholar
Best, J.P., Zechner, J., Shorubalko, I., Oboňa, J.V., Wehrs, J., Morstein, M., and Michler, J.: A comparison of three different notching ions for small-scale fracture toughness measurement. Scr. Mater. 112, 71 (2016).CrossRefGoogle Scholar
Armstrong, D.E.J., Rogers, M.E., and Roberts, S.G.: Micromechanical testing of stress corrosion cracking of individual grain boundaries. Scr. Mater. 61(7), 741 (2009).Google Scholar
Bergmann, G. and Vehoff, H.: Effect of environment on the brittle-to-ductile transition of pre-cracked NiAl single and polycrystals. Mater. Sci. Eng., A 192–193, 309 (1995).CrossRefGoogle Scholar
Thome, F., Göken, M., and Vehoff, H.: Study of the fracture behavior in soft and hard oriented NiAl single crystals by AFM. Intermetallics 7(3–4), 491 (1999).CrossRefGoogle Scholar
Ast, J., Przybilla, T., Maier, V., Durst, K., and Göken, M.: Microcantilever bending experiments in NiAl—Evaluation, size effects, and crack tip plasticity. J. Mater. Res. 29(18), 2129 (2014).Google Scholar
Wurster, S., Motz, C., and Pippan, R.: Characterization of the fracture toughness of micro-sized tungsten single crystal notched specimens. Philos. Mag. 92(14), 1803 (2012).Google Scholar
Bohnert, C., Schmitt, N.J., Weygand, S.M., Kraft, O., and Schwaiger, R.: Fracture toughness characterization of single-crystalline tungsten using notched micro-cantilever specimens. Int. J. Plast. 81, 1 (2016).CrossRefGoogle Scholar
Bergmann, G. and Vehoff, H.: Precracking of NiAl single crystals by compression-compression fatigue and its application to fracture toughness testing. Scr. Metall. Mater. 30(8), 969 (1994).Google Scholar
Iqbal, F., Ast, J., Göken, M., and Durst, K.: In situ micro-cantilever tests to study fracture properties of NiAl single crystals. Acta Mater. 60(3), 1193 (2012).CrossRefGoogle Scholar
ASTM International: ASTM E1820–13 Standard Test Method for Measurement of Fracture Toughness, Vol. 03.01 (ASTM International, West Conshohocken, 2014); pp. 1–54.Google Scholar
Rusović, N. and Warlimont, H.: The elastic behaviour of β2-NiAl alloys. Phys. Status Solidi A 44(2), 609 (1977).Google Scholar
Sih, G.C. and Liebowitz, H.: On the Griffith energy criterion for brittle fracture. Int. J. Solids Struct. 3(1), 1 (1967).Google Scholar
ASTM International: ASTM E399–90 Standard Test Method for Plane-strain Fracture Toughness of Metallic Materials, Vol. 03.01 (ASTM International, West Conshohocken, 1991); pp. 1–34.Google Scholar
Ebrahimi, F. and Shrivastava, S.: Brittle-to-ductile transition in NiAl single crystal. Acta Mater. 46(5), 1493 (1998).Google Scholar
Darolia, R., Lahrman, D., and Field, R.: The effect of iron, gallium and molybdenum on the room temperature tensile ductility of NiAl. Scr. Metall. Mater. 26(7), 1007 (1992).Google Scholar
Bradley, A.J. and Taylor, A.: An x-ray analysis of the nickel–aluminium system. Proc. R. Soc. A 159(896), 56 (1937).Google Scholar
Irwin, G.R.: Analysis of stresses and strains near the end of cracking traversing a plate. J. Appl. Mech. 24, 361 (1957).CrossRefGoogle Scholar
Noebe, R.D., Bowman, R.R., and Nathal, M.V.: Physical and mechanical properties of the B2 compound NiAl. Int. Mater. Rev. 38(4), 193 (1993).Google Scholar
Wei, Y. and Hutchinson, J.W.: Steady-state crack growth and work of fracture for solids characterized by strain gradient plasticity. J. Mech. Phys. Solids 45(8), 1253 (1997).Google Scholar
Broek, D. and Vlieger, H.: The Thickness Effect in Plane Stress Fracture Toughness (National Aerospace Institute, Amsterdam, Report 74032, 1974).Google Scholar
Kupka, D. and Lilleodden, E.T.: Mechanical testing of solid-solid interfaces at the microscale. Exp. Mech. 52(6), 649 (2012).Google Scholar