A comparison of models for predicting the true hardness of thin films

Iost, Alain; Guillemot, Gildas; Rudermann, Yann; Bigerelle, Maxence

doi:10.1016/j.tsf.2012.10.017

Cited by 29 publications

(13 citation statements)

References 27 publications

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“…Only few publications present in detail the determination of the elastic modulus and the hardness of thin hydroxyapatite sol-gel films (b 2000 nm in thickness) directly and properly from the indentation data. The determination of the mechanical properties of relatively thin coatings by nanoindentation often requires the application of models for separating the contribution of the substrate from the indentation data [13,14]. For hardness measurements, a model must be applied when the indenter displacement is higher than a given value, which depends both on coating thickness and the mechanical behavior of the coating, i.e.…”

Section: Introductionmentioning

confidence: 99%

Study of the mechanical behavior and corrosion resistance of hydroxyapatite sol–gel thin coatings on 316 L stainless steel pre-coated with titania film

Sidane

Chicot²,

Yala

et al. 2015

Thin Solid Films

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International audienceIn order to reinforce the clinical applications of hydroxyapatite (HAP) sol–gel coatings deposited onto 316 L stainless steel, we suggest the introduction of an intermediate thin layer of titania (TiO2) on the substrate. The titania sub-layer is introduced in order to improve both the corrosion resistance and the mechanical properties of the HAP/316 L stainless steel coated system. The two coatings, HAP and TiO2, were studied separately and afterwards, compared with the bi-layered coating. A film without any cracks is obtained under the optimum conditions in terms of annealing temperature, dipping rate and aging effect. Microstructural, morphological and profilometry analysis revealed the non-stoichiometric carbonated porous nature of the hydroxyapatite coatings, which were obtained after annealing at 500 °C during 60 min in the atmosphere. The obtained TiO2 coatings exhibit a dense and uniform surface. Addition of TiO2 as sub-layer of the HAP coating tends to increase the homogeneity and the crystallinity rate as compared to the HAP one.The mechanical properties, i.e. hardness and elastic modulus, are determined by means of nanoindentation experiments and the adhesion between the coating and substrate is estimated by scratch tests. The corrosion behavior is evaluated by potentiodynamic cyclic voltammetry tests. As a main result, the values of the elastic modulus and hardness, respectively of 30 GPa and 2.5 GPa, are relatively high for the HAP–TiO2 bilayer coating. This result allows the use of such coated material as a replacement material for hard tissues. The adhesion strength increased from 2925 mN up to 6430 mN after the addition of the TiO2 intermediate film. According to the Tafel's analysis, the 316 L stainless steel specimens coated with both HAP and titania layers (ECorr = − 234 mV, lCorr = 0.089 μA cm− 2) present a better resistance than the HAP-coated specimens (ECorr = − 460 mV, lCorr = 0.860 μA cm− 2)

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Section: Introductionmentioning

confidence: 99%

Study of the mechanical behavior and corrosion resistance of hydroxyapatite sol–gel thin coatings on 316 L stainless steel pre-coated with titania film

Sidane

Chicot²,

Yala

et al. 2015

Thin Solid Films

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“…At the same time the indenter penetration depth during microhardness testing was about 5-5.5 µm, which is 20-30% of the alloyed layer thickness. It is known that for accurate determination of the thin layer material microhardness the ratio of the indenter penetration depth and the film thickness should be at least 1:10 to avoid the influence of the substrate material [32]. Thus, in conditions of these experiments the influence of a softer copper substrate on the measured microhardness can take place.…”

Section: Resultsmentioning

confidence: 99%

Phase composition and mechanical properties of Cu–Ti alloys synthesized in the surface layer of copper by plasma impact on the Ti/Cu system

Cherenda

Basalai

Углов

et al. 2019

Vacuum

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Cu-Ti alloys synthesized in the surface layer of copper by means of preliminary Ti coating deposition and subsequent treatment by compression plasma flows have been investigated in this work. X-ray diffraction, scanning electron microscopy, energy-dispersion X-ray microanalysis, Auger electron spectroscopy, Vickers microhardness measurements and tribological tests were used for Cu-Ti alloys characterization. The findings showed that the increase of the energy absorbed by the surface layer during plasma treatment from 57 to 74 J/cm 2 per pulse resulted in the growth of the alloyed surface layer thickness from 15 to 19 µm, more homogeneous distribution of Ti in the alloyed layer and the decrease of Ti average concentration from 13.1 to 9.7 at.% in it. The supersaturated solid solution of titanium in copper is the main phase constituent of the alloyed layer after treatment at 74 J/cm 2 . The synthesized surface of the Cu-Ti alloy possesses enhanced strength and tribological properties.

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“…In a recent paper, Iost et al [51] analyzed the robustness of different models employed for the description of the composited hardness of coated systems, which involve the deposition of monolayer coatings, and the determination of the intrinsic hardness of both coating and substrate. This analysis encompassed the original models proposed by Jönsson and Hogmark [36], Korsunsky et al [39][40][41] and Puchi-Cabrera [42,43].…”

Section: Discussionmentioning

confidence: 99%

Modeling the composite hardness of multilayer coated systems

2015

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The change in the composite hardness with penetration depth derived from nanoindentation tests conducted on coated systems, which involve the deposition of multilayer coatings, in general exhibits a complex shape, as a consequence of the sequential contribution of each coating layer to the composite hardness during indentation loading. In spite that there are a number of models, which have been proposed for describing the change of the composite hardness with penetration depth for monolayer coatings, as well as for determining the coating and substrate hardness, very few research works have addressed the problem of describing this kind of data for multilayer coatings. In the present communication, a rational approach is proposed for extending two models widely used for the analysis of monolayer coatings, in order to describe the composite hardness data of multilayer coatings, as well as for determining the hardness of each individual layer and that of the substrate. Thus, a modified form of the models earlier advanced by Korsunsky et al. and Puchi-Cabrera, as well as their computational instrumentation, are proposed. The extension of both models to deal with multilayer coatings is conducted on the basis of the model developed by Iost et al., in order to adapt the Jönsson-Hogmark model to the analysis of indentation data of multilayer coatings. Such a methodology provides a means of computing the volume fraction of each individual layer in the coating, which contributes to the composite hardness. According to the results obtained, this scheme seems to be general enough to be applicable to different hardness models other than the Jönsson-Hogmark model. The proposed modified models are validated employing nanoindentation results obtained from a 2024-T6 aluminum alloy coated with a diamond-like carbon film, employing electroless NiP as intermediate layer. The advantages and disadvantages of the different models employed in the analysis are thoroughly discussed.

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A comparison of models for predicting the true hardness of thin films

Cited by 29 publications

References 27 publications

Study of the mechanical behavior and corrosion resistance of hydroxyapatite sol–gel thin coatings on 316 L stainless steel pre-coated with titania film

Study of the mechanical behavior and corrosion resistance of hydroxyapatite sol–gel thin coatings on 316 L stainless steel pre-coated with titania film

Phase composition and mechanical properties of Cu–Ti alloys synthesized in the surface layer of copper by plasma impact on the Ti/Cu system

Modeling the composite hardness of multilayer coated systems

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