Journal Home > Volume 2 , Issue 4

An unconventional method for determining the fracture resistance of brittle materials is discussed. This method employs a conical indenter to chip the rectangular edge of the specimen. Particular features of the method are the use of small specimens and the evaluation of the resistance of materials to the nucleation, initiation and propagation of a crack. It is shown that this method is somewhat similar to the Hertzian fracture method and to the way that early man selected stones to make tools and weapons. Measured data of the fracture resistance of ceramics is presented. It is confirmed that if a ceramic material is similar to the model material of linear elastic fracture mechanics (LEFM), then those fracture resistance values are directly proportional to the critical stress intensity factors (baseline). For elastic and inelastic ceramics, R-lines characterizing the fracture resistance to crack growth are plotted. It is shown that proportionality lines (edge chipping resistance versus critical stress intensity factor) may be straight lines for ceramics with similar structure (such as Y-TZP and Mg-PSZ). The effect of rounding of the conical indenter tip (10–800 µm) on chip scar shape is indicated. Other aspects in the fracture behavior of ceramics during edge chipping are also analyzed. The advantages and disadvantages of the method are discussed. Further studies in this mechanico-physical research area are suggested.


menu
Abstract
Full text
Outline
About this article

Edge chipping resistance of ceramics: Problems of test method

Show Author's information George A. GOGOTSI*( )
Pisarenko Institute for Problems of Strength, 2, Timiryazevskaya Str., 01014, Kiev, Ukraine

Abstract

An unconventional method for determining the fracture resistance of brittle materials is discussed. This method employs a conical indenter to chip the rectangular edge of the specimen. Particular features of the method are the use of small specimens and the evaluation of the resistance of materials to the nucleation, initiation and propagation of a crack. It is shown that this method is somewhat similar to the Hertzian fracture method and to the way that early man selected stones to make tools and weapons. Measured data of the fracture resistance of ceramics is presented. It is confirmed that if a ceramic material is similar to the model material of linear elastic fracture mechanics (LEFM), then those fracture resistance values are directly proportional to the critical stress intensity factors (baseline). For elastic and inelastic ceramics, R-lines characterizing the fracture resistance to crack growth are plotted. It is shown that proportionality lines (edge chipping resistance versus critical stress intensity factor) may be straight lines for ceramics with similar structure (such as Y-TZP and Mg-PSZ). The effect of rounding of the conical indenter tip (10–800 µm) on chip scar shape is indicated. Other aspects in the fracture behavior of ceramics during edge chipping are also analyzed. The advantages and disadvantages of the method are discussed. Further studies in this mechanico-physical research area are suggested.

Keywords: indentation, mechanical characterization, micromechanics, phase transformation, edge fracture (EF) method

References(29)

[1]
Broek D. Elementary Engineering Fracture Mechanics. Dordrecht: Kluwer Academic Publishers, 1986.
DOI
[2]
Irwin GR. Analysis of stresses and strains near the end of a crack traversing a plate. J Appl Mech 1957, 24: 361-364.
[3]
ISO 23146:2008. Fine ceramics (advanced ceramics, advanced technical ceramics)—Test methods for fracture toughness of monolithic ceramics— Single-edge V-notch beam (SEVNB) method. Gevena: ISO, 2008.
[4]
Evans AG, Faber KT. Crack-growth resistance of microcracking brittle materials. J Am Ceram Soc 1984, 67: 255-260.
[5]
Garvie RC, Hannink RH, Pascoe RT. Ceramic steel? Nature 1957, 258: 703-704.
[6]
Brumm A, Aziz F, van den Bergh GD, et al. Early stone technology on Flores and its implications for Homo floresiensis. Nature 2006, 441: 624-628.
[7]
Balter M. New light on revolutions that weren’t. Science 2012, 336: 530-531.
[8]
Griffith A. The phenomena of rupture and flow in solids. Phil Trans R Soc Lond A 1921, 221: 163-198.
[9]
Almond EA, McCormick NJ. Constant-geometry edge-flaking of brittle materials. Nature 1986, 321: 53-55.
[10]
Evans AG, Wilshaw TR. Quasi-static solid particle damage in brittle solids—I. Observations analysis and implications. Acta Metall 1976, 24: 939-956.
[11]
Fischer-Cripps AC. Introduction to Contact Mechanics, 2nd edn. New York: Springer, 2007.
DOI
[12]
McCormick NJ, Almond EA. Edge flaking of brittle materials. J Hard Mater 1990, 1: 25-51.
[13]
Morrell R, Gant AJ. Edge chipping of hard materials. Int J Refract Met H 2001, 19: 293-301.
[14]
Gogotsi GA, Galenko VI, Mudrik SP, et al. Fracture resistance estimation of elastic ceramics in edge flaking: EF baseline. J Eur Ceram Soc 2010, 30: 1223-1228.
[15]
Gogotsi GA. Fracture resistance of ceramics: Base diagram and R-line. Strength Mater 2006, 38: 261-270.
[16]
Gogotsi GA. Fracture toughness of ceramics and ceramic composites. Ceram Int 2003, 29: 777-784.
[17]
Gogotsi GA. Criteria of ceramics fracture (edge chipping and fracture toughness tests). Ceram Int 2013, 39: 3293-3300.
[18]
Gogotsi GA, Mudrik SP. Fracture barrier estimation by the edge fracture test method. Ceram Int 2009, 35: 1871-1875.
[19]
Readey MJ, Heuer AH, Steinbrech RW. Crack propagation in Mg-PSZ. MRS Proc 1986, 78: 107-120.
[20]
Wilshaw TR. The Hertzian fracture test. J Phys D: Appl Phys 1971, 4: 1567-1581.
[21]
Knott JF. Micromechanisms of fracture and the fracture toughness of engineering alloys. In Fracture. Taplin DMR, Ed. Canada: University of Waterloo Press, 1977: 61-92.
DOI
[22]
Batanova OA, Gogotsi GA, Matvienko YuG. Numerical analysis of edge chipping data. Ind Lab Diag Mater 2011, 77: 53-56. (in Russian)
[23]
Chai H. On the mechanics of edge chipping from spherical indentation. Int J Fracture 2011, 169: 85-95.
[24]
Guiberteau F, Padture NP, Lawn BR. Effect of grain size on Hertzian contact damage in alumina. J Am Ceram Soc 1994, 77: 1825-1831.
[25]
Drucker DC. Macroscopic fundamentals in brittle fracture. In Treatise on Fracture. Liebowitz H, Ed. New York: Academic Press, 1968: 473-531.
[26]
Gogotsi GA. The problem of the classification of low-deformation materials based on the features of their behavior under load. Strength Mater 1977, 9: 77-83.
[27]
Quinn J, Su L, Flanders L, et al. “Edge toughness” and material properties related to the machining of dental ceramics. Mach Sci Technol 2000, 4: 291-304.
[28]
Gogotsi GA, Mudrik SP, Quinn J. Edge toughness of silicon nitride ceramics: Method and results. In Proceedings of the International Conference on Novel Technologies in Power Metallurgy and Ceramics. Kiev: IPMS, 2003: 375-376.
[29]
Gogotsi GA, Mudrik SP. Glasses: New approach to fracture behavior analysis. J Non-Cryst Solids 2010, 356: 1021-1026.
Publication history
Copyright
Acknowledgements
Rights and permissions

Publication history

Received: 21 July 2013
Revised: 15 October 2013
Accepted: 30 October 2013
Published: 04 December 2013
Issue date: December 2013

Copyright

© The author(s) 2013

Acknowledgements

The author is grateful to V. Galenko for technical assistance.

Rights and permissions

Open Access: This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.

Return