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.
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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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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 -