Fracture toughness determination of fused silica by cube corner indentation cracking and pillar splitting

Bruns, Sebastian; Pethő, László; Minnert, Christian; Michler, Johann; Durst, Karsten

doi:10.1016/j.matdes.2019.108311

Cited by 42 publications

(15 citation statements)

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“…Switching indenter geometries from the rather blunt Berkovich to the sharp cube corner tip unifies the cracking behavior within the NBS2 series. Radial cracking becomes predominant with increasing indenter sharpness, which is in good accordance with the literature (Gross, 2012;Bruns et al, 2020). However, cube corner indentation is usually accompanied with traces of chipping and, depending on the degree of chipping, the indentations show significant differences in radial crack extension (Figure 6D), ruling out a quantification of cracking according to Lawn et al (1980).…”

Section: The Mechanical Propertiessupporting

confidence: 88%

“…Instrumented (nano-)indentation testing has become a widely used tool to investigate the deformation mechanisms of glass, as it activates a variety of possible responses: elastic contact, inelastic shear flow, densification and cracking (Rouxel, 2015;Yoshida et al, 2016;Januchta and Smedskjaer, 2019;Yoshida, 2019). Whereas, indentation-based methods to asses fracture toughness and their applicability to oxide glasses is controversially discussed in the literature (Bruns et al, 2017(Bruns et al, , 2020Rouxel and Yoshida, 2017;Yoshida, 2019), indentation testing remains one of the best solutions to compare glasses in terms of critical loads for crack initiation (Wada et al, 1974;Kato et al, 2010;Yoshida, 2019). Significant shifts in crack resistance have been observed upon chemical variations (Kato et al, 2010;Barlet et al, 2015;Malchow et al, 2015), different thermal histories (Malchow et al, 2015;Zehnder et al, 2017a), or upon compression (Januchta et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

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Influence of Al2O3 Addition on Structure and Mechanical Properties of Borosilicate Glasses

et al. 2020

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Alkali-borosilicate glasses are one of the most used types of glasses with a high technological importance. In order to optimize glasses for diverse applications, an understanding of the correlation between microscopic structure and macroscopic properties is of central interest in materials science. It has been found that the crack initiation in borosilicate glasses can be influenced by changes in network interconnectivity. In the NBS2 borosilicate glass system (74.0SiO 2 -20.7B 2 O 3 -4.3Na 2 O-1.0Al 2 O 3 in mol%) two subnetworks are present, i.e., a silicate and a borate network. Increasing cooling rates during processing were found to improve glasses crack resistance. Simultaneously, an increase in the network interconnectivity accompanied by an increasing capacity for densification were noticed. Their individual contribution to the mechanic response, however, remained unclear. In the present study the borosilicate glasses were systematically modified by addition of up to 4.0 mol% Al 2 O 3 . Changes in the network connectivity as well as the short-and medium-range order were characterized using Raman and NMR spectroscopy. Both the Raman and the 11 B NMR results show that four-fold-coordinated boron is converted into three-fold-coordination as the Al 2 O 3 content increases. Additionally, 27 Al NMR experiments show that aluminum is dominantly present in four-fold coordination. Aluminum-tetrahedra are thus charge balanced by sodium ions and incorporated into the silicate network. Finally, nanoindentation testing was employed to link the inherent glass structure and its network configuration to the mechanical glass response. It was found that the glass softens with increasing Al 2 O 3 content, which enhances the crack resistance of the borosilicate glass.

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Section: The Mechanical Propertiessupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Influence of Al2O3 Addition on Structure and Mechanical Properties of Borosilicate Glasses

et al. 2020

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“…The simulations indicate that the extent of densification is strongly linked to the hydrostatic pressure below the indenter, which does not exceed P = 10 GPa for all examined indenter geometries (Figure B: light grey sketched vertical line). Interestingly, this hydrostatic pressure corresponds remarkably well to fused silica's indentation hardness of about 9.6 GPa . According to Hill and Johnson the hydrostatic pressure saturates in a central region (inside the plastic zone) below the indenter.…”

Section: Resultssupporting

confidence: 65%

“…Interestingly, this hydrostatic pressure corresponds remarkably well to fused silica's indentation hardness of about 9.6 GPa. 50 According to Hill 51 and Johnson 48 the hydrostatic pressure saturates in a central region (inside the plastic zone) below the indenter. In Johnson's expanding cavity model the pressure acting within this so-called hydrostatic core corresponds approximately to the mean indentation contact pressure, ie the indentation hardness H, which is defined as the applied load per projected contact area of the indentation.…”

Section: Influences Of Fea Tip Geometry On the Densification Maximumentioning

confidence: 99%

Indentation densification of fused silica assessed by raman spectroscopy and constitutive finite element analysis

Bruns

Uesbeck²,

Fuhrmann

et al. 2020

J Am Ceram Soc

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Inelastic deformation of anomalous glasses manifests in shear flow and densification of the glass network; the deformation behavior during indentation testing is linked strongly to both processes. In this paper, the indentation densification field of fused silica is investigated using depth‐resolved Raman spectroscopy and finite element simulations. Through affecting the size of the indent, the normal load and the Raman laser spot size determine the spatial sampling resolution, leading to a certain degree of structural averaging. For appropriate combinations of normal load (indent size) and laser spot diameter, a maximum densification of 18.4% was found at the indent center. The indentation behavior was modeled by extended Drucker‐Prager‐Cap (DPC) plasticity, assuming a sigmoidal hardening behavior of fused silica with a densification saturation of 21%. This procedure significantly improved the reproduction of the experimental densification field, yielding a maximum densification of 18.2% directly below the indenter tip. The degree of densification was found to be strongly linked to the hydrostatic pressure limit below the indenter in accordance to Johnson's expanding cavity model (J. Mech. Phys. Solids, 18 (1970) 115). Based on the good overlap between FEA and Raman, an alternative way to extract the empirical correlation factor m, which scales structural densification to Raman spectroscopic observations, is obtained. This approach does not require the use of intensive hydrostatic compaction experiments.

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“…14, а или балку с надрезом, разрушаемую изгибом) невозможно ввиду больших размеров образцов, которые требуют стандарты [159,160]. Поэтому большинство авторов используют одну из трех альтернативных схем испытания: 1) классическую, с измерением [166][167][168]. Коротко опишем и сравним наиболее популярные методы разрушающих наномеханических испытаний и полученные результаты.…”

Section: разрушение в микро- субмикрои наношкалеunclassified

Наноиндентирование И Механические Свойства Материалов В Субмикро- И Наношкале. Недавние Результаты И Достижения (О Б З О Р)

Головин¹

2021

Физика Твердого Тела

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The review discusses the details of various materials mechanical behavior in submicro- and nanoscale. Significant advances in this scope result from the development of wide family of load based precise nanotesting techniques called nanoindentation. But nowadays, nanomechanical properties are studied not only by nanoindentation techniques in narrow sense, i.e. local loading of macro, micro and nanoscale objects. Nanomechanical load testing is discussed here within a wider scope employing precise deformation measurement with nanometer scale resolution caused by various types of low load application to the object under study including uniaxial compression or extension, shearing, bending or twisting, optionally accompanied by in situ monitoring sample microstructure using scanning and transmission electron microscopy and Laue microdiffraction technique. The main courses of experimental techniques development in recent ten years along with the results obtained using them in single, poly and nano crystalline materials, composites, films and coatings, amorphous solids and such biomaterials as tissues, living cells and macromolecules are described. Special attention is paid to deformation size effects and atomic mechanisms in nanoscale. This review is a natural continuation and development of the review published at Fiz.Tverd.Tela vol.50, issue 12, 2008 of the same author that discusses details of nanomechanical properties of solids. Current review includes wider range of nanomechanical testing concepts and recent achievements in the scope. The work was supported by RFBR grant for project #19-12-50235.

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Fracture toughness determination of fused silica by cube corner indentation cracking and pillar splitting

Cited by 42 publications

References 47 publications

Influence of Al2O3 Addition on Structure and Mechanical Properties of Borosilicate Glasses

Influence of Al2O3 Addition on Structure and Mechanical Properties of Borosilicate Glasses

Indentation densification of fused silica assessed by raman spectroscopy and constitutive finite element analysis

Наноиндентирование И Механические Свойства Материалов В Субмикро- И Наношкале. Недавние Результаты И Достижения (О Б З О Р)

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