Journal ArticleDOI
Superhard silicon nanospheres
William W Gerberich,William M. Mook,Christopher R. Perrey,C. B. Carter,Michael I. Baskes,Rajesh Mukherjee,A. Gidwani,Joachim Heberlein,Peter H. McMurry,Steven L. Girshick +9 more
TLDR
In this article, a prediction of observed hardnesses in the range of 20 − 50 GPa was made based upon a proposed length scale related to the size of nanospheres in the 20−50 nm radii range.Abstract:
Successful deposition and mechanical probing of nearly spherical, defect-free silicon nanospheres has been accomplished. The results show silicon at this length scale to be up to four times harder than bulk silicon. Detailed measurements of plasticity evolution and the corresponding hardening response in normally brittle silicon is possible in these small volumes. Based upon a proposed length scale related to the size of nanospheres in the 20– 50 nm radii range, a prediction of observed hardnesses in the range of 20– 50 GPa is made. The ramifications of this to computational materials science studies on identical volumes are discussed.read more
Citations
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Journal ArticleDOI
Size dependence of nanostructures: Impact of bond order deficiency
Chang Q. Sun,Chang Q. Sun +1 more
TL;DR: The BOLS correlation mechanism has been initiated and intensively verified as discussed by the authors, which has enabled the tunability of a variety of properties of a nanosolid to be universally reconciled to the effect of bond order deficiency of atoms at sites surrounding defects or near the surface edges of the nano-material.
Journal ArticleDOI
Mechanical properties of nanoparticles: basics and applications
Dan Guo,Guoxin Xie,Jianbin Luo +2 more
TL;DR: In this paper, the basic physics of the relevant interfacial forces to nanoparticles and the main measuring techniques are briefly introduced first, then, the theories and important results of the mechanical properties between nanoparticles or the nanoparticles acting on a surface, e.g., hardness, elastic modulus, adhesion and friction, as well as movement laws are surveyed.
Journal ArticleDOI
Atomistic modeling of interfaces and their impact on microstructure and properties
Yuri Mishin,Mark Asta,Ju Li +2 more
TL;DR: An overview of the most recent developments in the area of atomistic modeling with emphasis on interfaces and their impact on microstructure and properties of materials is given in this paper, along with some challenges and future research directions in this field.
Journal ArticleDOI
Indentation across size scales and disciplines: Recent developments in experimentation and modeling
TL;DR: Indentation is a remarkably flexible mechanical test due to its relative experimental simplicity as discussed by the authors, and the ease of implementation has made indentation a ubiquitous research tool for a number of different systems across size scales (nano to macro) and scientific/engineering disciplines.
Journal ArticleDOI
A new view of the onset of plasticity during the nanoindentation of aluminium
Andrew M. Minor,S. A. Syed Asif,Zhi-Wei Shan,Eric A. Stach,Edward Cyrankowski,Thomas J. Wyrobek,Oden L. Warren +6 more
TL;DR: Direct evidence is reported that plasticity in a dislocation-free volume of polycrystalline aluminium can begin at very small forces, remarkably, even before the first sustained rise in repulsive force, contrary to earlier assumptions that a dislocated-freevolume is necessary to achieve shear stresses near the theoretical shear strength of the material.
References
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Journal ArticleDOI
An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments
Warren C. Oliver,George M. Pharr +1 more
TL;DR: In this paper, the authors used a Berkovich indenter to determine hardness and elastic modulus from indentation load-displacement data, and showed that the curve of the curve is not linear, even in the initial stages of the unloading process.
Journal ArticleDOI
Indentation size effects in crystalline materials: A law for strain gradient plasticity
William D. Nix,Huajian Gao +1 more
TL;DR: In this article, the indentation size effect for crystalline materials can be accurately modeled using the concept of geometrically necessary dislocations, which leads to the following characteristic form for the depth dependence of the hardness: H H 0 1+ h ∗ h where H is the hardness for a given depth of indentation, h, H 0 is a characteristic length that depends on the shape of the indenter, the shear modulus and H 0.
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The deformation of plastically non-homogeneous materials
TL;DR: The geometrically necessary dislocations as discussed by the authors were introduced to distinguish them from the statistically storages in pure crystals during straining and are responsible for the normal 3-stage hardening.
Journal ArticleDOI
Modified embedded-atom potentials for cubic materials and impurities
TL;DR: In a comprehensive study, the modified embedded-atom method is extended to a variety of cubic materials and impurities, including metals, semiconductors, and diatomic gases, all of which exhibit different types of bonding.
Book
Introduction to dislocations
Derek Hull,H. M. Otte +1 more
TL;DR: In this article, the authors present an overview of dislocations in materials science and present a detailed discussion of the mechanisms of the dislocation and the mechanical strength of crystalline solids.
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