Journal ArticleDOI
Effect of a Reactive Environment on the Hertzian Strength of Brittle Solids
F. B. Langitan,B. R. Lawn +1 more
Reads0
Chats0
TLDR
In this article, two alternative models, both of which account for the observed detrimental effect of an environment on the Hertzian strength but which predict slight differences in the growth of the cone crack, are offered.Abstract:
Hertizan fracture theory, previously developed for ideal brittle solids fractured under essentially environment‐free conditions, is here modified to allow for an interaction between the growing cone crack and a reactive environment. Two alternative models, both of which account for the observed detrimental effect of an environment on the Hertzian strength but which predict slight differences in the growth of the cone crack, are offered. The first is based on a surface‐energy‐lowering concept and the second on a subcritical‐crack‐growth concept. The theoretical implications of these two models are examined in the light of Hertzian fracture experiments on abraded glass slabs in different test environments. Observations of the growth of the cone crack in fatigue experiments favor the second model for glass. The advantages of the Hertzian test as a tool for the study of environmental effects on the fracture strength of brittle solids in general are discussed in relation to more conventional fracture tests.read more
Citations
More filters
Journal ArticleDOI
Indentation fracture: principles and applications
Brian R. Lawn,Rodney Wilshaw +1 more
TL;DR: The basic principles and practical applications of indentation fracture are reviewed in this article, with a focus on the application of fracture fracture in the field of orthogonal fracture repair and alignment.
Journal ArticleDOI
Indentation of Ceramics with Spheres: A Century after Hertz
TL;DR: In this article, the authors review the nature and mechanics of damage induced in ceramics by spherical indenters, from the classical studies of Hertz over a century ago to the present day.
Journal ArticleDOI
Microfracture beneath point indentations in brittle solids
Brian R. Lawn,Michael V. Swain +1 more
TL;DR: In this paper, the authors investigated the microfracture patterns observed around point indentations in brittle solids and derived the means for predetermining, in principle, the depth of fracture damage under given point loading conditions.
Journal ArticleDOI
Fracture indentation beneath flat and spherical punches
R. Mouginot,Daniel Maugis +1 more
TL;DR: In this paper, the authors investigated the mechanics of crack initiation and propagation under axisymmetric flat punches and showed that the Auerbach range corresponds to the relatively flat maximum of the envelope of the G againstc/a curves for various starting radii.
Journal ArticleDOI
Mechanical Characterization of Dental Ceramics by Hertzian Contacts
TL;DR: Hertzian indentation testing is proposed as a protocol for evaluating the role of microstructure in the mechanical response of dental ceramics, with results showing the most brittle responses are observed in the fine glass-ceramics and porcelain; conversely, the most quasi-plastic responses are observation in the coarse glass-cers and zirconia.
References
More filters
Journal ArticleDOI
The Phenomena of Rupture and Flow in Solids
TL;DR: In this article, the authors investigated the effect of surface scratches on the mechanical strength of solids, and some general conclusions were reached which appear to have a direct bearing on the problem of rupture, from an engineering standpoint, and also on the larger question of the nature of intermolecular cohesion.
Journal ArticleDOI
Direct Measurements of the Surface Energies of Crystals
TL;DR: In this paper, the surface energies of several simple crystals have been measured at −196°C by means of quantitative cleavage experiments and the measured values of their respective surface energies (ergs/cm2) are: 340, 1200, 450, 280, 230, 1240, and 105.
Journal ArticleDOI
Plastic flow in glass
TL;DR: The authors discusses the evidence for flow, evaluates the flow stresses by re-interpretation of the indentation hardness figures, and shows that flow stresses are much lower than the theoretical cohesive strengths.