Spherical indentation of an elastic bilayer: A modification of the perturbation approach

2008 ◽  
Vol 23 (11) ◽  
pp. 2935-2943 ◽  
Author(s):  
Jae Hun Kim ◽  
Chad S. Korach ◽  
Andrew Gouldstone
Keyword(s):  
Analytic Solution ◽  
Effective Modulus ◽  
Spherical Indentation ◽  
Perturbation Approach ◽  
Instrumented Indentation ◽  
Flat Punch ◽  
First Order ◽  
Property Measurement ◽  
Film Substrate ◽  
Contact Size

Accurate mechanical property measurement of films on substrates by instrumented indentation requires a solution describing the effective modulus of the film/substrate system. Here, a first-order elastic perturbation solution for spherical punch indentation on a film/substrate system is presented. Finite element method (FEM) simulations were conducted for comparison with the analytic solution. FEM results indicate that the new solution is valid for a practical range of modulus mismatch, especially for a stiff film on a compliant substrate. It also shows that effective modulus curves for the spherical punch deviates from those of the flat punch when the thickness is comparable to contact size.

A Perturbation-Based Method for Extracting Elastic Properties during Spherical Indentation of an Elastic Film/Substrate Bilayer

2008 ◽  
Vol 1139 ◽  
Author(s):  
Jae Hun Kim ◽  
Andrew Gouldstone ◽  
Chad S. Korach
Keyword(s):  
Mechanical Property ◽  
Finite Element Method ◽  
Analytic Solution ◽  
Spherical Indentation ◽  
Instrumented Indentation ◽  
Fem Simulations ◽  
First Order ◽  
Elastic Film ◽  
Property Measurement ◽  
Film Substrate

AbstractAccurate mechanical property measurement of films on substrates by instrumented indentation requires a solution describing the effective modulus of the film/substrate system. Here, a first-order elastic perturbation solution for spherical punch indentation on a film/substrate system is presented. Finite element method (FEM) simulations were conducted for comparison with the analytic solution. FEM results indicate that the new solution is valid for a practical range of modulus mismatch, especially for a stiff film on a compliant substrate.

Nonlinear self-phase-modulation effects: a vectorial first-order perturbation approach

1995 ◽  
Vol 20 (5) ◽  
pp. 456 ◽  
Author(s):  
Velko P. Tzolov ◽  
Nicolas Godbout ◽  
Suzanne Lacroix ◽  
Marie Fontaine
Keyword(s):  
Phase Modulation ◽  
Order Perturbation ◽  
Perturbation Approach ◽  
Self Phase Modulation ◽  
First Order ◽  
First Order Perturbation

Instrumented indentation microscope applied to the elastoplastic indentation contact mechanics of coating/substrate composites

2009 ◽  
Vol 24 (6) ◽  
pp. 1950-1959 ◽  
Author(s):  
N. Hakiri ◽  
A. Matsuda ◽  
M. Sakai
Keyword(s):  
Contact Area ◽  
Film Coating ◽  
Instrumented Indentation ◽  
Thin Film Coating ◽  
Composite Systems ◽  
Indentation Tests ◽  
Film Substrate ◽  
Contact Parameters

In instrumented indentation tests for a thin film coating on a substrate (film/substrate composite), it is well known that the substrate-affected contact area estimated through conventional approximations includes significant uncertainties, leading to a crucial difficulty in determining the elastic modulus and the contact hardness. To overcome this difficulty, an instrumented indentation microscope that enables researchers to make an in situ determination of the contact area is applied to an elastoplastic film on substrates having various values of their elastic moduli. Using the indentation microscope, the substrate-affected indentation contact parameters including contact hardness of the film/substrate composites are determined directly as well as quantitatively without any undesirable assumptions and approximations associated with the contact area estimate. The effect of a stiffer substrate on the contact profile of impression is significant, switching the profile from sinking in to piling up during penetration, and resulting in the substrate-affected contact hardness being highly enhanced at deeper penetrations. Through the present experimental study, it is demonstrated how efficient that instrumented indentation microscopy is in determining the substrate-affected elastoplastic contact parameters of film/substrate composite systems.

scholarly journals Numerical verification for instrumented spherical indentation techniques in determining the plastic properties of materials

2009 ◽  
Vol 24 (12) ◽  
pp. 3653-3663 ◽  
Author(s):  
Taihua Zhang ◽  
Peng Jiang ◽  
Yihui Feng ◽  
Rong Yang
Keyword(s):  
Numerical Experiments ◽  
Spherical Indentation ◽  
Numerical Verification ◽  
Instrumented Indentation ◽  
Plastic Properties ◽  
Wide Range ◽  
Validity Range ◽  
Indentation Tests ◽  
Properties Of Materials ◽  
Indentation Methods

Instrumented indentation tests have been widely adopted for elastic modulus determination. Recently, a number of indentation-based methods for plastic properties characterization have been proposed, and rigorous verification is absolutely necessary for their wide application. In view of the advantages of spherical indentation compared with conical indentation in determining plastic properties, this study mainly concerns verification of spherical indentation methods. Five convenient and simple models were selected for this purpose, and numerical experiments for a wide range of materials are carried out to identify their accuracy and sensitivity characteristics. The verification results show that four of these five methods can give relatively accurate and stable results within a certain material domain, which is defined as their validity range and has been summarized for each method.

The Study of the Formation and Growth of Ni-Al Spinel Using a New, Thin-Film, Specimen Geometry

1985 ◽  
Vol 60 ◽  
Author(s):  
Y. Kouh Simpson ◽  
C. B. Carter
Keyword(s):  
Thin Film ◽  
Nickel Oxide ◽  
Direct Observation ◽  
Alumina Substrate ◽  
Specimen Geometry ◽  
Nickel Aluminate ◽  
New Approach ◽  
First Order ◽  
Film Specimen ◽  
Film Substrate

AbstractThe formation of nickel-aluminate spinel during the reaction between nickel oxide and alumina has been studied by a new approach which utilizes a thin-film substrate of alumina. It is found that the spinel grows in either near- or exact-topotactic alignment along the edges of the thin-film substrate. It also grows on and into the surface of the substrate, but the deviation from exact topotaxy then tends to be larger. The topotactic relationship is such that the (0001) of the alumina is parallel or nearly parallel to the {111} planes of the spinel with <1100> parallel to <110>. A second orientation relatioship is found where the {1120} of the alumina is parallel or nearly parallel to the {111} planes of the spinel; <1100> is again parallel to <110>. First order twin boundaries are found to be common in the spinel particles which have grown on the edge of the thin alumina substrate. Direct observation of the change in the orientation of the spinel twins with respect to the alumina substrate after reannealing is reported. The morphology of the various types of spinel particles is discussed briefly.

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