Journal ArticleDOI
An explanation of the indentation size effect in ceramics
TLDR
In this paper, a quantitative model is proposed to explain the indentation size effect (ISE) often observed in the hardness response of hard brittle materials, namely that hardness is observed to increase with decreasing indentation sizes.Abstract:
A quantitative model is proposed to explain the indentation size effect (ISE) often observed in the hardness response of hard brittle materials, namely that hardness is observed to increase with decreasing indentation size. The model is based on a mixed elastic/plastic materials deformation response whereby plastic deformation occurs in a discrete manner progressively to relieve stresses created by elastic flexure of the surface at the edges of the indentation. During unloading of the indenter, recovery of the elastic increment of deformation, which precedes each new band of plastic deformation, results in the indentation appearing smaller than expected, particularly as the indentation sizes decrease to approach the scale of the plastic deformation band spacing. The model fits observed experimental data well and analysis of hardness/size data in this way is shown to allow both a bulk hardness value and a characteristic deformation band scale to be calculated for a given sample.read more
Citations
More filters
Journal ArticleDOI
Different approaches to superhard coatings and nanocomposites
TL;DR: In this paper, different approaches to the preparation of superhard coatings such as intrinsically superhard materials, coatings whose hardness is enhanced by energetic ion bombardment during deposition, and nanostructured super-hard materials are discussed with the emphasis on the question of how to distinguish between the different mechanisms of hardness enhancement in thin coatings.
Journal ArticleDOI
On the hardness of coated systems
TL;DR: In this article, the hardness of a number of coated systems has been measured using a variety of experimental techniques ranging from traditional macro-Vickers indentation to ultra-low-load depth-sensing nanoindentation.
Journal ArticleDOI
The Indentation Size Effect: A Critical Examination of Experimental Observations and Mechanistic Interpretations
TL;DR: In this article, the authors review experimental observations of the size effect on the behavior of crystalline metals and examine prevailing ideas on the mechanisms responsible for the effect in light of recent experimental observations and computer simulations.
Journal ArticleDOI
The deformation behavior of ceramic crystals subjected to very low load (nano)indentations
TL;DR: In this article, a software-controlled hardness tester (Nanoindenter) operating in the load range 2-60 mN was used to characterize the deformation structures associated with these very small-scale hardness impressions.
Journal ArticleDOI
On the reverse indentation size effect and microhardness measurement of solids
TL;DR: In this article, the reverse type of indentation size effect (ISE), where the apparent microhardness increases with increasing applied test load, was critically examined for the experimentally reported data for a number of single crystals differing in crystal structure and chemical bond, using the theoretical models reported in the literature.
References
More filters
Book
The Hardness of Metals
TL;DR: Hardness measurements with conical and pyramidal indenters as mentioned in this paper have been used to measure the area of contact between solids and the hardness of ideal plastic metals. But they have not yet been applied to the case of spherical indenters.
Book
The Science of hardness testing and its research applications : based on papers presented at a symposium of the American Society for Metals, October 18 to 20, 1971
J. H. Westbrook,Hans Conrad +1 more
Journal ArticleDOI
The micro-hardness of metals at very low loads
TL;DR: The micro-hardness of gold has been investigated over a range of indentation sizes from 0.5 mm to 0.2 μm using loads down to 1.0 mg.
Related Papers (5)
An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments
Warren C. Oliver,George M. Pharr +1 more
Indentation size effects in crystalline materials: A law for strain gradient plasticity
William D. Nix,Huajian Gao +1 more