Elastic–plastic characterization of thin films using nanoindentation technique

Shan, Zhaohui; Sitaraman, Suresh K.

doi:10.1016/s0040-6090(03)00663-1

Cited by 70 publications

(31 citation statements)

References 14 publications

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“…8,11,12,18,20,23 Table 1 shows the Young's Modulus (E) and the Poisson coefficient (ν) that were obtained in the literature and were used in the present simulation. [24][25] The values of K and n were obtained from Equation (2) In this Equation (2), ε u is the ultimate strain, ε o is the yield strain, σ u is the ultimate strength, σ o is the yield stress and n is the strain-hardening coefficient, as seen previously. These values were obtained using the experimental numerical methodology developed by Dias and Godoy (2010).…”

Section: Numerical Proceduresmentioning

confidence: 99%

Determination of Film Thickness Through Simulation of Vickers Hardness Testing

2017

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In recent decades, changes in the surface properties of materials have been used to improve their tribology characteristics. However, this improvement depends on the process, treatment time and, essentially, the thickness of this surface film layer. Physical vapor deposition (PVD) has been used to increase the surface hardness of metallic materials. The aim of the present study was to propose a numerical-experimental method to assess the thickness (l) of films deposited by PVD. To reach this objective, Vickers experimental hardness data (H V ) assays were combined with numerical simulation to study the behavior of this property as a function of maximum penetration depth of the indenter (h max ) into the film/substrate conjugate. A strategy was developed to combine the numerical results of the H x h max /l curve with Vickers experimental hardness data (H V ). This methodology was applied to a TiNcoated M2 tool steel conjugate. The mechanical properties of the studied materials were also determined. The thickness results calculated for this conjugate were compatible with their experimental data.

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Section: Numerical Proceduresmentioning

confidence: 99%

Determination of Film Thickness Through Simulation of Vickers Hardness Testing

2017

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“…Cracking occurs when the thermal stress in the film exceeds the yield stress of Ti (ca. 700 MPa for thin Ti films [24]). In our experiments this can be expected to happen for a maximum temperature of 1800-2000 K, corresponding to a laser fluence of *250 mJ cm .…”

Section: Nanosecond Irradiationmentioning

confidence: 99%

Laser pulse duration dependence of blister formation on back-radiated Ti thin films for BB-LIFT

et al. 2016

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The influence of the laser pulse duration on the mechanism of blister formation in the particle transfer technique, blister-based laser-induced forward transfer, was investigated. Pulses from a fs Ti:Sapphire laser (120 fs, 800 nm) and from a ns Nd:YAG laser (7 ns, 532 nm) were used to directly compare blister formation on thin titanium films of ca. 300 nm thickness, deposited on glass. The different blister morphologies were compared and contrasted by using optical microscopy and atomic force microscopy. The results provide evidence for different blister formation mechanisms: for fs pulses the mechanism is predominantly ablation at the metal-glass interface accompanied by confined plasma expansion and deformation of the remaining metal film; for ns pulses it is heating accompanied by thermal expansion of the metal film.

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“…From experimental data, the modulus and hardness of titanium thin film are, respectively, 128 GPa and 2.1 GPa. [29] The latter is estimated from its yield stress. Because the crystalline Ti substrate in our MD model only contains eight atomic layers, its hardness may be larger than that experimentally reported.…”

Section: Resultsmentioning

confidence: 99%

Indentation Behavior of Zr-Based Metallic-Glass Films via Molecular-Dynamics Simulations

Wang

Chu

et al. 2010

Metall Mater Trans A

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Molecular dynamics (MD) models of the Zr-based metallic-glass film (Zr 47 Cu 31 Al 13 Ni 9 , in atomic percent) were constructed by simulating sputter depositions on the titanium substrate. The as-deposited films were used as initial structures for subsequent nanoindentation simulations. For the deposition simulations, a many-body, tight-binding (TB) potential was adopted for interatomic interactions among the multiple species of atoms. The interactions between the metallic atoms and working gas (Ar + ) were modeled with the pairwise Moliere potential. The TB potential parameters for unlike atoms were chosen to be the algebraic average of those for like ones, and hence, the MD simulations provide qualitative information. The deposition simulations revealed an amorphous morphology in the as-deposited films. Indentation simulations with a right-angle conical indenter tip showed a homogeneous flow to form pileups on the surface of the metallic glass around the indent. The pileup index calculated from MD is consistent with that obtained from the experiment. Moreover, our MD results show that the pileup index exhibits anomalies, which are defined as unusual changes in the values of the pileup index, around the experimentally found glass-transformation temperature through in situ indentation simulations at elevated temperatures. From indentation load-displacement curves at various temperatures, indentation modulus and hardness obtained from MD simulations were in qualitative agreement with experimental findings in terms of their decreasing rates with respect to the temperature. Three-dimensional atomic-strain calculations revealed strain localization and propagation of shear bands under the indenter tip at their initial evolution stages after the formation of shear transformation zones. In addition, higher loading rates decrease hardness, cause larger disturbed regions under the indent, and enlarge shear-banding patterns.

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Elastic–plastic characterization of thin films using nanoindentation technique

Cited by 70 publications

References 14 publications

Determination of Film Thickness Through Simulation of Vickers Hardness Testing

Determination of Film Thickness Through Simulation of Vickers Hardness Testing

Laser pulse duration dependence of blister formation on back-radiated Ti thin films for BB-LIFT

Indentation Behavior of Zr-Based Metallic-Glass Films via Molecular-Dynamics Simulations

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