Low friction Ta-C films with hydrogen reservoirs

Jari Koskinen (Corresponding Author), Helena Ronkainen, Simo Varjus, Tatu Muukkonen, Kenneth Holmberg, T. Sajavaara

    Research output: Contribution to journalArticleScientificpeer-review

    13 Citations (Scopus)

    Abstract

    Diamond-like tetrahedral amorphous carbon (ta-C) films, which contain no hydrogen and high content of sp3 bonds have a very high hardness and elastic modulus (up to 600 GPa). They have also excellent tribological properties in atmospheres that contain humidity (50% RH) or also when submerged in water. However, in dry atmospheres the co-efficient of sliding friction against bearing steel, for instance, increases to values of over 0.7. In this paper ta-C films were modified by adding hydrogen to the films. The ta-C films were deposited by using non-filtered pulsed vacuum arc deposition in the ambient pressure of hydrogen and hydrocarbon gases. A novel layered structure containing titanium layers with hydrogen and carbon have also been grown by using filtered metal arc in combination with the pulsed carbon arc. The hydrogen content and the composition of the films were measured by using time-of-flight elastic recoil detection analysis (TOF-ERDA). The hardness of the films was measured by nanoindentation. The tribological performance of the coatings were determined by using pin-on-disk tests. The counter part material was steel (AISI 52100), the normal load applied 5 N and the sliding velocity 0.02 m/s. In the modified films the hydrogen content was up to 16 at.% in ta-C and up to approximately 50 at.% in the titanium layers. A co-efficient of friction of approximately 0.2 at dry atmosphere was measured for hydrogen-containing ta-C and also for layered structures where a hydrogen-containing Ti layer was buried under a hydrogen free ta-C layer. The results indicate that the lowered co-efficient of friction is a result of hydrogen transport to the contact surfaces with the aid of surface diffusion through the pinholes of the ta-C layer.
    Original languageEnglish
    Pages (from-to)1030-1035
    Number of pages6
    JournalDiamond and Related Materials
    Volume10
    Issue number3-7
    DOIs
    Publication statusPublished - 2001
    MoE publication typeA1 Journal article-refereed
    Event11th European Conference on Diamond, Diamond-like Materials, Carbon Nanotubes, Nitrides and Silicon Carbide - Porto, Portugal
    Duration: 3 Sep 20008 Sep 2000

    Fingerprint

    Hydrogen
    Amorphous carbon
    Friction
    Carbon films
    Amorphous films
    Steel
    Titanium
    Bearings (structural)
    Carbon
    Hardness
    Diamond
    Surface diffusion
    Nanoindentation
    Hydrocarbons
    Diamonds
    Atmospheric humidity
    Elastic moduli
    Gases
    Metals
    Vacuum

    Cite this

    Koskinen, Jari ; Ronkainen, Helena ; Varjus, Simo ; Muukkonen, Tatu ; Holmberg, Kenneth ; Sajavaara, T. / Low friction Ta-C films with hydrogen reservoirs. In: Diamond and Related Materials. 2001 ; Vol. 10, No. 3-7. pp. 1030-1035.
    @article{8cbcc8c627d64c2b85bf47d7c616d0f3,
    title = "Low friction Ta-C films with hydrogen reservoirs",
    abstract = "Diamond-like tetrahedral amorphous carbon (ta-C) films, which contain no hydrogen and high content of sp3 bonds have a very high hardness and elastic modulus (up to 600 GPa). They have also excellent tribological properties in atmospheres that contain humidity (50{\%} RH) or also when submerged in water. However, in dry atmospheres the co-efficient of sliding friction against bearing steel, for instance, increases to values of over 0.7. In this paper ta-C films were modified by adding hydrogen to the films. The ta-C films were deposited by using non-filtered pulsed vacuum arc deposition in the ambient pressure of hydrogen and hydrocarbon gases. A novel layered structure containing titanium layers with hydrogen and carbon have also been grown by using filtered metal arc in combination with the pulsed carbon arc. The hydrogen content and the composition of the films were measured by using time-of-flight elastic recoil detection analysis (TOF-ERDA). The hardness of the films was measured by nanoindentation. The tribological performance of the coatings were determined by using pin-on-disk tests. The counter part material was steel (AISI 52100), the normal load applied 5 N and the sliding velocity 0.02 m/s. In the modified films the hydrogen content was up to 16 at.{\%} in ta-C and up to approximately 50 at.{\%} in the titanium layers. A co-efficient of friction of approximately 0.2 at dry atmosphere was measured for hydrogen-containing ta-C and also for layered structures where a hydrogen-containing Ti layer was buried under a hydrogen free ta-C layer. The results indicate that the lowered co-efficient of friction is a result of hydrogen transport to the contact surfaces with the aid of surface diffusion through the pinholes of the ta-C layer.",
    author = "Jari Koskinen and Helena Ronkainen and Simo Varjus and Tatu Muukkonen and Kenneth Holmberg and T. Sajavaara",
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    language = "English",
    volume = "10",
    pages = "1030--1035",
    journal = "Diamond and Related Materials",
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    Koskinen, J, Ronkainen, H, Varjus, S, Muukkonen, T, Holmberg, K & Sajavaara, T 2001, 'Low friction Ta-C films with hydrogen reservoirs', Diamond and Related Materials, vol. 10, no. 3-7, pp. 1030-1035. https://doi.org/10.1016/S0925-9635(00)00488-X

    Low friction Ta-C films with hydrogen reservoirs. / Koskinen, Jari (Corresponding Author); Ronkainen, Helena; Varjus, Simo; Muukkonen, Tatu; Holmberg, Kenneth; Sajavaara, T.

    In: Diamond and Related Materials, Vol. 10, No. 3-7, 2001, p. 1030-1035.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Low friction Ta-C films with hydrogen reservoirs

    AU - Koskinen, Jari

    AU - Ronkainen, Helena

    AU - Varjus, Simo

    AU - Muukkonen, Tatu

    AU - Holmberg, Kenneth

    AU - Sajavaara, T.

    PY - 2001

    Y1 - 2001

    N2 - Diamond-like tetrahedral amorphous carbon (ta-C) films, which contain no hydrogen and high content of sp3 bonds have a very high hardness and elastic modulus (up to 600 GPa). They have also excellent tribological properties in atmospheres that contain humidity (50% RH) or also when submerged in water. However, in dry atmospheres the co-efficient of sliding friction against bearing steel, for instance, increases to values of over 0.7. In this paper ta-C films were modified by adding hydrogen to the films. The ta-C films were deposited by using non-filtered pulsed vacuum arc deposition in the ambient pressure of hydrogen and hydrocarbon gases. A novel layered structure containing titanium layers with hydrogen and carbon have also been grown by using filtered metal arc in combination with the pulsed carbon arc. The hydrogen content and the composition of the films were measured by using time-of-flight elastic recoil detection analysis (TOF-ERDA). The hardness of the films was measured by nanoindentation. The tribological performance of the coatings were determined by using pin-on-disk tests. The counter part material was steel (AISI 52100), the normal load applied 5 N and the sliding velocity 0.02 m/s. In the modified films the hydrogen content was up to 16 at.% in ta-C and up to approximately 50 at.% in the titanium layers. A co-efficient of friction of approximately 0.2 at dry atmosphere was measured for hydrogen-containing ta-C and also for layered structures where a hydrogen-containing Ti layer was buried under a hydrogen free ta-C layer. The results indicate that the lowered co-efficient of friction is a result of hydrogen transport to the contact surfaces with the aid of surface diffusion through the pinholes of the ta-C layer.

    AB - Diamond-like tetrahedral amorphous carbon (ta-C) films, which contain no hydrogen and high content of sp3 bonds have a very high hardness and elastic modulus (up to 600 GPa). They have also excellent tribological properties in atmospheres that contain humidity (50% RH) or also when submerged in water. However, in dry atmospheres the co-efficient of sliding friction against bearing steel, for instance, increases to values of over 0.7. In this paper ta-C films were modified by adding hydrogen to the films. The ta-C films were deposited by using non-filtered pulsed vacuum arc deposition in the ambient pressure of hydrogen and hydrocarbon gases. A novel layered structure containing titanium layers with hydrogen and carbon have also been grown by using filtered metal arc in combination with the pulsed carbon arc. The hydrogen content and the composition of the films were measured by using time-of-flight elastic recoil detection analysis (TOF-ERDA). The hardness of the films was measured by nanoindentation. The tribological performance of the coatings were determined by using pin-on-disk tests. The counter part material was steel (AISI 52100), the normal load applied 5 N and the sliding velocity 0.02 m/s. In the modified films the hydrogen content was up to 16 at.% in ta-C and up to approximately 50 at.% in the titanium layers. A co-efficient of friction of approximately 0.2 at dry atmosphere was measured for hydrogen-containing ta-C and also for layered structures where a hydrogen-containing Ti layer was buried under a hydrogen free ta-C layer. The results indicate that the lowered co-efficient of friction is a result of hydrogen transport to the contact surfaces with the aid of surface diffusion through the pinholes of the ta-C layer.

    U2 - 10.1016/S0925-9635(00)00488-X

    DO - 10.1016/S0925-9635(00)00488-X

    M3 - Article

    VL - 10

    SP - 1030

    EP - 1035

    JO - Diamond and Related Materials

    JF - Diamond and Related Materials

    SN - 0925-9635

    IS - 3-7

    ER -