Effects of indenter radius on the critical load in scratch testing

Ishiguro, Hiroshi; Ishii, Yoshiro

doi:10.1016/s0257-8972(02)00718-1

Cited by 75 publications

(36 citation statements)

References 10 publications

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“…This is, again, in agreement with the results obtained by other authors [6,7]. It must however be taken into account that Ichimura and Ishii [10] also note that the effect of indenter geometry is more noticeable with increasing substrate hardness; therefore, the modified test may be more sensitive to substrate hardness variations compared to a Rockwell C hardness indenter.…”

Section: Room Temperature Scratch Characterizationsupporting

confidence: 91%

“…This difference is due to the different morphology of the tip: compared to the spherical contact generated using a Rockwell C indenter, the modified test generates an entirely different stress field. This is consistent with the existing literature; the effect of indenter radius on critical load has been studied experimentally and analytically by various authors, such as Randall et al [9] or Ichimura and Ishii [10]. These studies conclude that sharper indenters result in significantly reduced failure load; however, rankings obtained using each individual indenter geometry are maintained.…”

Section: Room Temperature Scratch Characterizationsupporting

confidence: 88%

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High temperature scratch testing of hard PVD coatings deposited on surface treated tool steel.

Pujante

Vilaseca

Casellas

et al. 2014

Surface and Coatings Technology

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Scratch testing is one of the most usual characterisation techniques for systems with thin hard coatings. Scratch tests are performed at run at room temperature, due to the risk of degradation of the indenter diamond tip at high temperature and added test complexity. However, results obtained at room temperature may differ from final system performance in high temperature applications, due to factors such as substrate thermal softening. In this work, a simple and a robust test for the mechanical characterization of hard PVD coatings at high temperature and open atmosphere has been developed, based on a modification of the scratch test where the diamond tip is replaced by a WC indenter. The test has been used to evaluate the effect of temperature up to 500 ºC on commercial PVD AlCrN coating deposited on tool steel subject to different surface treatments. Results show a decrease in the failure load Lc2 with increasing temperature, and a very noticeable effect of substrate nitriding. Highlights(i) A modified scratch test for high temperature applications has been developed (ii) Performance of AlCrN-coated 1.2344 has been studied up to 500ºC (iii) Effect of substrate nitriding on system performance up to 500ºC has been explored (iv) Results show the relationship between performance and substrate load bearing capacity ABSTRACTScratch testing is one of the most usual characterisation techniques for systems with thin hard coatings. Scratch tests are performed at run at room temperature, due to the risk of degradation of the indenter diamond tip at high temperature and added test complexity.However, results obtained at room temperature may differ from final system performance in high temperature applications, due to factors such as substrate thermal softening.In this work, a simple and a robust test for the mechanical characterization of hard PVD coatings at high temperature and open atmosphere has been developed, based on a modification of the scratch test where the diamond tip is replaced by a WC indenter. The test has been used to evaluate the effect of temperature up to 500 ºC on commercial PVD AlCrN coating deposited on tool steel subject to different surface treatments. Results show a decrease in the failure load Lc2 with increasing temperature, and a very noticeable effect of substrate nitriding.

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Section: Room Temperature Scratch Characterizationsupporting

confidence: 91%

Section: Room Temperature Scratch Characterizationsupporting

confidence: 88%

High temperature scratch testing of hard PVD coatings deposited on surface treated tool steel.

Pujante

Vilaseca

Casellas

et al. 2014

Surface and Coatings Technology

View full text Add to dashboard Cite

show abstract

“…The scratch test was initially thought of as primarily an adhesion test, with higher critical loads directly corresponding to more adherent films, but there is now a substantive body of evidence showing that it is the mechanical properties of the film and substrate that exert a significant influence on the deformation behaviour rather than the adhesion strength alone [28][29][30][31][32][33][34][35][36][37][38]. The critical load is dependent on many factors in addition to the interfacial strength.…”

Section: Introductionmentioning

confidence: 99%

Nano-scratch testing of (Ti,Fe)N x thin films on silicon

Beake

Vishnyakov

Harris

2017

Surface and Coatings Technology

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Thin films of (Ti,Fe)Nx have been produced on silicon wafers with a wide range of compositions and mechanical properties to investigate correlations between the mechanical properties measured by indentation and crack resistance in the highly loaded sliding contact in a nano-scratch test. The nano-scratch test data on the thin films using a well-worn Berkovich indenter with ~1 m end radius were supported by high resolution scanning electron microscopic (SEM) imaging and analytical stress modelling. The results show that mechanical properties of the coating, its thickness and the substrate properties all influence the deformation process. They affect the critical loads required, the type of failures observed and their location relative to the moving probe. The differences in coating mechanical properties affect how the interface is weakened (i.e. by initial substrate or coating yielding or both) and determine the deformation failure mechanism. The load dependence of the friction coefficient provides details of the sliding contact zone and the location of failure relative to the sliding probe. Improved performance was achieved at intermediate hardness and H 3 /E 2 in the nano-scratch tests on thin films. The friction and modelling results strongly suggest that failure at low load on the hardest coatings is due to a combination of high tensile stress at the 2 rear of the contact zone and substrate yield. Designing thin films for protective coatings with in-built dissipative structures (such as soft and low elastic modulus inclusions) and mechanisms to combat stress may be a more successful route to optimise their toughness in highly loaded sliding conditions than aiming to minimise plasticity by increasing their hardness.

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“…Although it is known how the critical force is changed if the measurement conditions are changed, and the values can be converted into those expected from standard measurement, it would require expert knowledge to determine the new rules and their impact on the system, [5,6]. The rules and their weights in the Table 3 are designed in accordance with the expert knowledge and statements in the [3,6,[26][27][28][29][30]]. The new if-then rules of adhesion identified by measured critical force depending on the measurement conditions are mentioned in Table 3, [5,6].…”

Section: Fuzzy Rule Based Expert System For Evaluation Of Adhesionmentioning

confidence: 99%

The Evaluation of the Practical Adhesion Strength of Biocompatible Thin Films by Fuzzy Logic Expert System and International Standards

Socha¹,

Kutílek²,

Vítečková³

2013

Journal of Electrical Engineering

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This work focuses on describing an evaluation method used in nano-and micro-thin films based on fuzzy logic expert systems. The aim is the elimination of comparison complications with mechanical properties of tin films, practical adhesion being one of the most important characteristic of tin films. The basic method for evaluating the practical adhesion strength is scratch test method, while the issue is that research teams use measurement methods based on the non-uniform measurement conditions of adhesion of biocompatible thin films. The authors tested new evaluation method and procedure based on international standards and fuzzy rule based expert system in order to eliminate the problem of comparison of practical adhesion of the films. The article concentrates on testing and using the fuzzy logic expert system designed based on international standards for evaluating adhesion of thin films in nano and micro dimensions. The materials used for tests of the fuzzy expert system were DLC biocompatible layers and substrate a titanium alloy Ti6Al4V.

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Effects of indenter radius on the critical load in scratch testing

Cited by 75 publications

References 10 publications

High temperature scratch testing of hard PVD coatings deposited on surface treated tool steel.

High temperature scratch testing of hard PVD coatings deposited on surface treated tool steel.

Nano-scratch testing of (Ti,Fe)N x thin films on silicon

The Evaluation of the Practical Adhesion Strength of Biocompatible Thin Films by Fuzzy Logic Expert System and International Standards

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