Finite Element Modeling of Nanoindentation Measurements of Crystalline and Amorphous Si

2000 ◽  
Vol 649 ◽  
Author(s):  
J. A. Knapp ◽  
D. M. Follstaedt ◽  
S. M. Myers ◽  
G. A. Petersen
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Yield Criterion ◽  
Phase Changes ◽  
Element Modeling ◽  
Atomic Force ◽  
Nanoindentation Testing ◽  
Amorphous Si ◽  
Indentation Measurement

ABSTRACTNanoindentation testing of amorphous Si layers, formed by self-ion implantation, has been performed, and their mechanical properties compared to crystalline Si. The data was analyzed using finite element modeling of the indentation measurement, allowing the properties of the thin amorphous layers to be separated from those of the underlying material. By modeling the materials as isotropic, elastic-plastic solids with the Mises yield criterion, the amorphous Si is shown to have a hardness about 15% lower than crystalline Si and an elastic modulus about 10% lower. Electron and atomic force microscopies of the indents indicate that the amorphous Si does not undergo phase changes during indentation, and that it may be somewhat more ductile than crystalline Si.

scholarly journals Hardening of Nickel Alloys by Ion Implantation of Titanium and Carbon

1996 ◽  
Vol 444 ◽  
Author(s):  
S. M. Myers ◽  
D. M. Follstaedt ◽  
J. A. Knapp ◽  
T. R. Christenson
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Surface Layer ◽  
Ion Implantation ◽  
Finite Element Modeling ◽  
Yield Stress ◽  
Nickel Alloys ◽  
Element Modeling ◽  
Order Of Magnitude ◽  
Amorphous Surface

AbstractDual ion implantation of titanium and carbon was shown to produce an amorphous surface layer in annealed bulk nickel, in electroformed Ni, and in electroformed Ni7 5Fe 2 5. Diamond-tip nanoindentation coupled with finite-element modeling quantified the elastic and plastic mechanical properties of the implanted region. The amorphized matrix, with a thickness of about 100 nm, has a yield stress of approximately 6 GP and an intrinsic hardness near 16 GPa, exceeding by an order of magnitude the corresponding values for annealed bulk Ni. Implications for micro-electromechanical systems are discussed.

scholarly journals Evaluating Mechanical Properties of Thin Layers using Nanoindentation and Finite-Element Modeling: Implanted Metals and Deposited Layers

1996 ◽  
Vol 438 ◽  
Author(s):  
J. A. Knapp ◽  
D. M. Follstaedt ◽  
J. C. Barbour ◽  
S. M. Myers ◽  
J. W. Ager ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Yield Stress ◽  
Young’S Modulus ◽  
Layer Thickness ◽  
Young's Modulus ◽  
Thin Layers ◽  
Element Modeling ◽  
Surface Modified

AbstractWe present a methodology based on finite-element modeling of nanoindentation data to extract reliable and accurate mechanical properties from thin, hard films and surface-modified layers on softer substrates. The method deduces the yield stress, Young's modulus, and hardness from indentations as deep as 50% of the layer thickness.

The Study of Wrinkling Mechanism of Plasma-Treated Microphase-Separated Polyurethane Surface

2018 ◽  
Vol 773 ◽  
pp. 3-9 ◽  
Author(s):  
Ilya A. Morozov ◽  
Anton Y. Beliaev ◽  
Roman I. Izyumov
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Elastic Modulus ◽  
Finite Element Modeling ◽  
Layer Surface ◽  
Element Modeling ◽  
Compression Deformation ◽  
Good Accordance ◽  
Nitrogen Ions ◽  
External Strain

Stiff coating on the phase-separated soft polyurethane substrate under the compression deformation is investigated by the finite element modeling (FEM). External strain leads to the wrinkling of layer surface, which is characterized by a set of wavelengths and amplitudes. The influence of the thickness and stiffness of the layer, elastic modulus of the substrate on the structural-mechanical properties of the deformed surface is studied. The results of the model are in good accordance with the experiment (plasma immersion ion impanation of nitrogen ions into the polyurethane substrate) and allowed to estimate the modulus of the coating and the deformation of the surface.

Computing Thin Film Mechanical Properties With the Oliver and Pharr Method

1999 ◽  
Vol 593 ◽  
Author(s):  
P.J. Wolff ◽  
B.N. Lucas ◽  
E.G. Herbert
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Dimensional Analysis ◽  
Film Properties ◽  
Element Modeling ◽  
Indentation Tests

ABSTRACTA commonly used technique to compute mechanical properties from indentation tests is the Oliver and Pharr method. Using dimensional analysis and finite element modeling, this paper investigates errors when the Oliver and Pharr method is used to compute thin film properties.

Hall–Petch relationship in pulsed-laser deposited nickel films

2004 ◽  
Vol 19 (1) ◽  
pp. 218-227 ◽  
Author(s):  
J.A. Knapp ◽  
D.M. Follstaedt
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Pulsed Laser ◽  
Fused Silica ◽  
Thin Layers ◽  
Element Modeling ◽  
Petch Relationship ◽  
Grain Sizes ◽  
Dislocation Movement

Thin-film mechanical properties can be measured using nanoindentation combined with detailed finite element modeling. This technique was used for a study of very fine grained Ni films, formed using pulsed-laser deposition on fused silica, sapphire, and Ni substrates. The grain sizes in the films were characterized by electron microscopy, and the mechanical properties were determined by ultra-low load indentation, analyzed using finite element modeling to separate the mechanical properties of the thin layers from those of the substrates. Some Ni films were deposited at high temperature or annealed after deposition to enlarge the grain sizes. The observed hardnesses and grain sizes in these thin Ni films are consistent with the empirical Hall–Petch relationship for grain sizes ranging from a few micrometers to as small as 10 nm, suggesting that deformation occurs preferentially by dislocation movement even in such nanometer-size grains.

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