scholarly journals Mechanical Properties of Evaporated Gold Films. Hard Substrate Effect Correction

2008 ◽  
Vol 1086 ◽  
Author(s):  
Ke Du ◽  
Xiaolu Pang ◽  
Chi Chen ◽  
Alex A. Volinsky
Keyword(s):  
Mechanical Properties ◽  
Indentation Depth ◽  
Gold Film ◽  
Gold Films ◽  
Substrate Effect ◽  
Berkovich Indenter ◽  
Film Hardness ◽  
Polycrystalline Gold ◽  
Area Variation ◽  
Hard Substrates

AbstractNanoindentation tests using the Berkovich indenter tip were performed on 50 and 200 nm thick polycrystalline gold films deposited on hard substrates. Gold film hardness increased with the indentation depth due to the influence of the substrate. A procedure based on the Joslin-Oliver method was introduced to correct for the substrate effect. The method utilizes the fact that the measured elastic modulus does not change significantly with the indentation depth, which allows reducing the contact area variation used in the hardness calculation.

Indenter Tip Dependence in the Determination of Elastic Modulus in Polymers

2013 ◽  
Author(s):  
Seyed Hamid Reza Sanei ◽  
F. Alisafaei ◽  
Chung-Souk Han
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Elastic Modulus ◽  
Indentation Depth ◽  
Length Scale ◽  
Berkovich Indenter ◽  
Thin Wires ◽  
Length Scale Dependent Deformation ◽  
Nanoindentation Experiment

The two most common outputs of nanoindentation experiment are hardness and elastic modulus. Length scale dependent deformation in polymers has however been observed in different experiments such as microbeam bending, torsional thin wires and indentation testing which may affect the mechanical testing. Unlike in metals where the size dependency is attributed to necessary geometry dislocations, the origin of length scale dependent deformation in polymers is not well understood. In this study, elastic modulus of polydimethylsiloxane (PDMS) is determined using both Berkovich and spherical tips. Observing different trends for elastic modulus upon the change of indentation depth using these two different tips brings up the question which tip should be used to get the real mechanical properties of PDMS which is discussed here. Surface roughness, surface effects and the imperfection of the Berkovich indenter tip are negligible at the studied length scale.

Study of rough growth fronts of evaporated polycrystalline gold films

2004 ◽  
Vol 22 (4) ◽  
pp. 1767-1772 ◽  
Author(s):  
C. Munuera ◽  
J. A. Aznárez ◽  
E. Rodrı́guez-Cañas ◽  
A. I. Oliva ◽  
M. Aguilar ◽  
...  
Keyword(s):  
Gold Films ◽  
Polycrystalline Gold

scholarly journals Determination of mechanical properties by nanoindentation independently of indentation depth measurement

2012 ◽  
Vol 27 (19) ◽  
pp. 2551-2560 ◽  
Author(s):  
Gaylord Guillonneau ◽  
Guillaume Kermouche ◽  
Sandrine Bec ◽  
Jean-Luc Loubet
Keyword(s):  
Mechanical Properties ◽  
Indentation Depth ◽  
Depth Measurement ◽  
Image Position

Abstract

scholarly journals Application of the nanoindentation method in assessing of properties of cement composites modified with silica-magnetite nanostructures

2018 ◽  
Vol 163 ◽  
pp. 02002 ◽  
Author(s):  
Elzbieta Horszczaruk ◽  
Roman Jedrzejewski ◽  
Jolanta Baranowska ◽  
Ewa Mijowska
Keyword(s):  
Mechanical Properties ◽  
Magnetite Nanoparticles ◽  
Positive Influence ◽  
Cement Matrix ◽  
Core Shell ◽  
Indentation Modulus ◽  
Cement Composites ◽  
Interfacial Zone ◽  
Berkovich Indenter ◽  
The Core

The results of investigation of the cement composites modified with 5% of silica-magnetite nanostructures of the core-shell type are presented in the paper. The nanoindentation method employing three-sided pyramidal Berkovich indenter was used in the research. The mechanical properties and microstructure of the modified cement composites were evaluated on the basis of the values of hardness and indentation modulus measured inside the cement matrix and in the aggregate-paste interfacial zone. The results were compared with those obtained for the reference composites without nanostructures. The positive influence of the presence of silica-magnetite nanoparticles on the tested properties was found out.

Tem Study of Yielding in Polycrystalline Gold Thin Films

1997 ◽  
Vol 505 ◽  
Author(s):  
Kwame Owusu-Boahen ◽  
Alexander H. King
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Rock Salt ◽  
Gold Films ◽  
Plastic Yielding ◽  
Transmission Electron ◽  
Mean Grain Size ◽  
Polycrystalline Gold ◽  
Individual Grains

ABSTRACTWe have used transmission electron microscopy (TEM) to study the microstructure of thin gold films which were grown on 〈100〉 rock salt. The samples were annealed on the rock salt substrate or on a gold TEM specimen grid. Films annealed on rock salt had a larger mean grain size than those annealed on TEM grids. All of the annealed films have a 〈111〉 preferred orientation. Several cracks are observed in the film annealed on rock salt. Plastic yielding of the film was identified by the presence of dislocations, and is caused by tensile stress derived from grain growth. In spite of the uniform texture of the films, the observed dislocations were concentrated only in some individual grains, while their surrounding grains remained dislocation-free. Yielded grains showed no difference of orientation that would lead to higher Schmid factors, so other predictors of yielding must be considered.

Deterministic Contact Model of a Rough Surface Against a Flat-Layered Surface

2004 ◽  
Author(s):  
H. R. Pasaribu ◽  
D. J. Schipper
Keyword(s):  
Mechanical Properties ◽  
Rough Surface ◽  
Contact Area ◽  
Indentation Depth ◽  
Normal Load ◽  
Contact Model ◽  
Real Contact Area ◽  
Single Asperity ◽  
Real Contact ◽  
Effective Mechanical Properties

The effective mechanical properties of a layered surface vary as a function of indentation depth and the values of these properties range between the value of the layer itself and of the substrate. In this paper, a layered surface is modelled like a solid that has effective mechanical properties as a function of indentation depth by assuming that the layer is perfectly bounded to the substrate. The normal load as a function of indentation depth of sphere pressed against a flat layered surface is calculated using this model and is in agreement with the experimental results published by El-Sherbiney (1975), El-Shafei et al. (1983), Tang & Arnell (1999) and Michler & Blank (2001). A deterministic contact model of a rough surface against a flat layered surface is developed by representing a rough surface as an array of spherically shaped asperities with different radii and heights (not necessarily Gaussian distributed). Once the data of radius and height of every single asperity is obtained, one can calculate the number of asperities in contact, the real contact area and the load carried by the asperities as a function of the separation.

DETERMINATION OF VISCOELASTIC PROPERTIES OF THE PERIODONTAL LIGAMENT USING NANOINDENTATION TESTING AND NUMERICAL MODELING

2016 ◽  
Vol 16 (06) ◽  
pp. 1650089 ◽  
Author(s):  
HUIXIANG HUANG ◽  
WENCHENG TANG ◽  
YU YANG ◽  
BIN WU ◽  
BIN YAN
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Periodontal Ligament ◽  
Alveolar Bone ◽  
Spherical Indenter ◽  
Berkovich Indenter ◽  
Zener Model ◽  
Nanoindentation Experiment ◽  
Creep Models ◽  
Good Agreement

Viscoelasticity of the periodontal ligament (PDL) plays an important role in load transmission between tooth and alveolar bone, as well as tooth movement. This paper provides a novel nanoindentation experiment in combination with a rheological model to characterize the viscoelastic mechanical properties of the PDL. Two creep models of the indentation experiments with a Berkovich and a spherical indenter based on Zener model were developed. The hardness and reduced modulus were determined by using the Berkovich indenter. The parameters were identified through curve fittings. The fitting results show that the creep models are both in good agreement with the experimental data. Meanwhile, the models were both validated by comparing the numerical curves for load–depth relationship in loading segment with the corresponding experimental data. It is found that the spherical indenter is more suitable for testing the viscoelastic mechanical properties of the PDL than Berkovich indenter. Hence, the nanoindentation experiment with spherical indenter was simulated to further evaluate the Zener model by finite element analysis. The good agreement between the simulated results and experimental data demonstrates that the Zener model is capable of describing the viscoelastic mechanical behavior of the PDL.

A Method to Determine Fracture Toughness Using Berkovich Indenter for Bulk Materials

2013 ◽  
Vol 331 ◽  
pp. 456-460
Author(s):  
Min He ◽  
Duan Hu Shi ◽  
Feng Yang ◽  
Ning Zhang ◽  
Hua Feng Guo
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Penetration Depth ◽  
Effective Elastic Modulus ◽  
Berkovich Indenter ◽  
Bulk Materials ◽  
Ductile Materials ◽  
Penetration Depths ◽  
Determine Fracture Toughness

An indentation approach with Berkovich indenter is proposed to determine fracture toughness for ductile materials. With decrease of effective elastic modulus, an approximate linear relationship between logarithmic plastic penetration depth and logarithmic effective elastic modulus, and a quadratic polynomial relationship between the plastic penetration depths and penetration loads are exhibited by indentation investigation with Berkovich indenter. The damage constructive equation of effective elastic modulus is proposed to determine the critical effective elastic modulus at the fracture point, which is the key problem to calculate the indentation energy to fracture. The critical plastic penetration depth is identified after the critical effective elastic modulus can be predicted by conventional mechanical properties. The fracture toughness is calculated according to the equation of penetration load, plastic penetration depth and the critical plastic penetration depth.

Texture of Gold-Palladium Couples

1997 ◽  
Vol 472 ◽  
Author(s):  
Young S. Chung ◽  
Keenan Evans ◽  
William Glaunsinger
Keyword(s):  
Thin Films ◽  
Silicon Dioxide ◽  
Seed Layer ◽  
Substrate Surface ◽  
Diffusion Mechanism ◽  
Strong Dependence ◽  
Gold Films ◽  
X Ray Diffraction ◽  
Pole Figures ◽  
Polycrystalline Gold

ABSTRACTThe crystal textures of polycrystalline films of gold-palladium couples on an oxidized silicon (100) substrates were investigated via x-ray diffraction (XRD) pole figures. Studies were performed on both as-deposited and thermally annealed films. Scanning electron microscopy (SEM) was used to examine the microstructures of the seed layer thin films as deposited. The {111} texture formation of gold-palladium thin film couples displayed a strong dependence on the nature of the underlying seed layer. Gold films deposited on a palladium seed layer revealed much less degree of {111} texture, than gold films deposited directly on a silicon dioxide surface. In contrast, palladium films deposited on polycrystalline gold films showed a higher degree of {111} texture, compared to palladium films deposited directly on silicon dioxide. The {111} texture of annealed gold-palladium alloy thin films was greater for palladium on gold than for gold on palladium. These results are interpreted in terms of the gold-palladium diffusion mechanism and the interaction of the condensing metals with the oxygens of the SiO2 substrate surface.

Sign in / Sign up

Export Citation Format

Share Document