Indentation and scratch testing of DLC-Zr coatings on ultrafine-grained titanium processed by high-pressure torsion

Wang, Chuan Ting; Escudeiro, A.; Polcar, Tomáš; Cavaleiro, A.; Wood, R.J.K.; Gao, Nong; Langdon, Terence G.

doi:10.1016/j.wear.2012.12.033

Cited by 48 publications

(36 citation statements)

References 51 publications

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“…The maximum von Mises stresses are typically far into the substrate at the critical load and substrate yield occurs before the coatings fail [39]. In a recent study, Wang and co-workers reported that the critical load for coating failure on a range of DLC and TiN coatings on titanium alloys did not depend on coating composition, but correlated directly with the hardness of the substrate [40]. The significance of substrate yield was emphasized by cross-sectional profiles of the scratch depth at failure which were much larger than the coating thickness.…”

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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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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“…Morshed [9] sugere que ao otimizar as condições de ataque iônico com argônio é possível maximizar a adesividade e minimizar tensões residuais, sem alterar de forma significativa a dureza destes filmes. Apesar da extensa literatura sobre o aumento da adesividade, a caracterização desta propriedade se mantém principalmente qualitativa [10][11][12]. Entre diversos ensaios, a indentação Rockwell C, descrita na norma VDI3198, e os ensaios de riscamento são as maneiras mais comuns de se medir a adesividade de filmes de DLC [10][11][12][13][14].…”

Section: Introductionunclassified

“…Apesar da extensa literatura sobre o aumento da adesividade, a caracterização desta propriedade se mantém principalmente qualitativa [10][11][12]. Entre diversos ensaios, a indentação Rockwell C, descrita na norma VDI3198, e os ensaios de riscamento são as maneiras mais comuns de se medir a adesividade de filmes de DLC [10][11][12][13][14]. No presente estudo, ao invés de comparar aspectos morfológicos das indentações com padrões estabelecidos pela norma VDI3198, foi realizada uma comparação numérica através da quantificação da área desplacada através da análise de imagens produzidas por microscopia ótica.…”

Section: Introductionunclassified

Avaliação Da Adesão De Filmes Multifuncionais: Comparação Entre Testes De Indentação E Riscamento

Giacomelli¹,

Mattos²,

Soprano³

et al. 2018

ABM Proceedings

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ResumoA adesão de revestimentos multifuncionais em substratos moles é de extrema importância para o comportamento tribológico desta importante classe de tratamentos superficiais. Mais especificamente, testes de indentação e de riscamento são bastante utilizados na medição desta propriedade. No presente estudo, a adesão de filmes de DLC do tipo a-C:H depositados em aço baixo carbono nitretado foi investigada através de testes de indentação e riscamento. Os revestimentos foram produzidos através de PECVD em substratos de aço 1020 com dois acabamentos superficiais: lixado (Sq = 0,184 µm) e polido (Sq = 0,002 µm). Foram realizados testes de indentação Rockwell C e a adesão foi quantificada através da medição da área desplacada em imagens obtidas através de microscopia ótica. Esta análise produziu resultados semi-quantitativos, eliminando a análise qualitativa subjetiva sugerida pela norma VDI3198. Ainda, testes de riscamento foram realizados nas mesmas amostras com o mesmo indentador para que uma comparação entre ambas as técnicas pudesse ser estabelecida. Por fim, o método apresentado mostrou resultados coerentes, onde amostras com menor carga crítica apresentaram uma maior área desplacada. Amostras lixadas apresentaram um desempenho inferior em relação a adesividade. Palavras-chave: Diamond-like carbon; Adesão; Topografia; Aço nitretado. ASSESSMENT OF MULTIFUNCTIONAL COATING ADHESION: COMPARISON BETWEEN INDENTATION AND SCRATCH TESTS AbstractThe adhesion of multifunctional coatings on soft substrates is of paramount importance in the tribological behavior of this important class of surface treatment. In particular, scratch and indentation tests have been extensively used in order to assess this property. In this paper, the adhesion of a-C:H diamond-like carbon films deposited on nitrided low carbon steel was evaluated by indentation and scratch tests. The coatings were produced by PECVD onto 1020 steel substrates with two different surface finishing: ground (Sq = 0.184 µm) and polished (Sq = 0.002 µm). Indentation tests using a Rockwell diamond indenter were conducted and the adhesion evaluated by measuring the spalling region on images obtained by using optical microscopy. The analysis of the spalling regions produced semi-quantitative results, eliminating the subjective qualitative analysis proposed by the standard method VDI 3198. In addition, scratch tests were performed using the same indenter and a comparison between the two techniques was established. Finally, the method presented coherent results, where films with higher critical loads presented lower spalled areas. Ground samples presented an overall poorer adhesion performance.

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“…Hybrid coatings combined with layers of W and Zr-DLC are used to improve the coating properties, surface smoothness and tightness included. The use of diamond-like coatings (which is a novel solution in the field of surface engineering, offering high thermal resistance, good conductivity, and high hardness) has considerably improved the quality of the tested materials [15,16].…”

Section: Introductionmentioning

confidence: 99%

Application of Coatings Made by Plasma Spray and PVD Methods for Protection of Graphite Moulds

Nejman

Richert

Zawadzka

2016

mafe

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Powłoki ochronne nakładane metodami natrysku plazmowego oraz PVD na grafitowe krystalizatory przemysłowe AbstractThe results of our research on the application of coatings for protecting industrial casting molds are presented. Tests were carried out on graphite molds with deposited Al 2 O 3 coatings containing the addition of glassy carbon and with W/Zr/DLC coatings, both examined after the process of pouring molds with molten aluminum bronze. The coatings were applied by two different methods; i.e., plasma spraying in the case of Al 2 O 3 + glassy carbon coating and PVD in the case of W/Zr/DLC coating. Reference tests were also conducted on graphite molds without coating. The use of protective coatings on graphite molds seems to be an effective solution. Studies have shown that coatings have good resistance during the casting process. The liquid metal sticking to the surface did not penetrate deep inside the graphite mold. The use of coating technology reduces the amount of downtime necessary to replace worn molds and increases the efficiency of the casting process. Keywords: graphite molds, protective coatings, plasma spraying, PVD Streszczenie W pracy przedstawiono wyniki badań dotyczące zastosowania powłok do ochrony grafitowych krystalizatorów przemysłowych. Badaniom poddano krystalizator grafitowy bez naniesionej powłoki, jak i z powłoką Al 2 O 3 z dodatkiem węgla szklistego otrzymaną metodą natrysku plazmowego oraz krystalizator z powłoką W/Zr/DLC otrzymaną metodą PVD. Przeprowadzone badania dowodzą, że zastosowanie powłok w celu ochrony powierzchni krystalizatorów może być skutecznym rozwiązaniem. Badania wykazały, że zarówno powłoki ceramiczne Al 2 O 3 + węgiel szklisty, jak i powłoka W/Zr-DLC zapewniają ochronę krystalizatora w trakcie kontaktu z ciekłym medium. Badania strukturalne oraz analiza składu chemicznego zostały przeprowadzane z zastosowaniem skaningowej mikroskopii elektronowej (HITACHI SU-70). Słowa kluczowe: krystalizatory grafitowe, powłoki ochronne, natrysk plazmowy, PVD

show abstract

Indentation and scratch testing of DLC-Zr coatings on ultrafine-grained titanium processed by high-pressure torsion

Cited by 48 publications

References 51 publications

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

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

Avaliação Da Adesão De Filmes Multifuncionais: Comparação Entre Testes De Indentação E Riscamento

Application of Coatings Made by Plasma Spray and PVD Methods for Protection of Graphite Moulds

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