Abstract
This paper presents the results of a systematic study demonstrating how controlled or targeted tribochemistry can lead to super-low friction and wear in diamond-like carbon (DLC) films. Specifically, how hydrogen can lead to dramatic reductions in the friction and wear of hydrogen-free DLC films which otherwise experience high friction and severe wear losses. When sliding tests are performed with a hydrogen-free DLC film in an inert gas (like Ar), the friction coefficients were in the range of 0.4 to 0.7 and it wore out rather quickly. However, when the same tests were run under the 1333. Pa partial pressure of hydrogen, the friction coefficients were reduced by factors of more than 10 and the wear damage became very difficult to quantify. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analyses provided strong chemical evidence that the sliding contact surfaces of these films underwent tribochemical reactions with hydrogen effectively passivating dangling bonds of surface carbon atoms, which is believed to be responsible for ultralow friction and wear. In an effort to rule out the possibility of contamination and confirm the pivotal role of hydrogen in lubricity of DLC films, we ran similar tests with the same hydrogen-free DLC in deuterium (an isotope of hydrogen) and achieved essentially the same level of reduction in friction. TOF-SIMS clearly confirmed the formation of a deuterium-rich tribofilm on rubbing surfaces thus confirming the critical role of tribochemistry in super-low friction and wear of DLC.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 241-246 |
| Number of pages | 6 |
| Journal | Surface and Coatings Technology |
| Volume | 257 |
| DOIs | |
| State | Published - Oct 25 2014 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Chemistry(all)
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry
Cite this
}
Effect of tribochemistry on lubricity of DLC films in hydrogen. / Erdemir, A.; Eryilmaz, O. L.; Kim, Seong.
In: Surface and Coatings Technology, Vol. 257, 25.10.2014, p. 241-246.Research output: Contribution to journal › Article
TY - JOUR
T1 - Effect of tribochemistry on lubricity of DLC films in hydrogen
AU - Erdemir, A.
AU - Eryilmaz, O. L.
AU - Kim, Seong
PY - 2014/10/25
Y1 - 2014/10/25
N2 - This paper presents the results of a systematic study demonstrating how controlled or targeted tribochemistry can lead to super-low friction and wear in diamond-like carbon (DLC) films. Specifically, how hydrogen can lead to dramatic reductions in the friction and wear of hydrogen-free DLC films which otherwise experience high friction and severe wear losses. When sliding tests are performed with a hydrogen-free DLC film in an inert gas (like Ar), the friction coefficients were in the range of 0.4 to 0.7 and it wore out rather quickly. However, when the same tests were run under the 1333. Pa partial pressure of hydrogen, the friction coefficients were reduced by factors of more than 10 and the wear damage became very difficult to quantify. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analyses provided strong chemical evidence that the sliding contact surfaces of these films underwent tribochemical reactions with hydrogen effectively passivating dangling bonds of surface carbon atoms, which is believed to be responsible for ultralow friction and wear. In an effort to rule out the possibility of contamination and confirm the pivotal role of hydrogen in lubricity of DLC films, we ran similar tests with the same hydrogen-free DLC in deuterium (an isotope of hydrogen) and achieved essentially the same level of reduction in friction. TOF-SIMS clearly confirmed the formation of a deuterium-rich tribofilm on rubbing surfaces thus confirming the critical role of tribochemistry in super-low friction and wear of DLC.
AB - This paper presents the results of a systematic study demonstrating how controlled or targeted tribochemistry can lead to super-low friction and wear in diamond-like carbon (DLC) films. Specifically, how hydrogen can lead to dramatic reductions in the friction and wear of hydrogen-free DLC films which otherwise experience high friction and severe wear losses. When sliding tests are performed with a hydrogen-free DLC film in an inert gas (like Ar), the friction coefficients were in the range of 0.4 to 0.7 and it wore out rather quickly. However, when the same tests were run under the 1333. Pa partial pressure of hydrogen, the friction coefficients were reduced by factors of more than 10 and the wear damage became very difficult to quantify. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analyses provided strong chemical evidence that the sliding contact surfaces of these films underwent tribochemical reactions with hydrogen effectively passivating dangling bonds of surface carbon atoms, which is believed to be responsible for ultralow friction and wear. In an effort to rule out the possibility of contamination and confirm the pivotal role of hydrogen in lubricity of DLC films, we ran similar tests with the same hydrogen-free DLC in deuterium (an isotope of hydrogen) and achieved essentially the same level of reduction in friction. TOF-SIMS clearly confirmed the formation of a deuterium-rich tribofilm on rubbing surfaces thus confirming the critical role of tribochemistry in super-low friction and wear of DLC.
UR - http://www.scopus.com/inward/record.url?scp=85027956570&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85027956570&partnerID=8YFLogxK
U2 - 10.1016/j.surfcoat.2014.08.002
DO - 10.1016/j.surfcoat.2014.08.002
M3 - Article
AN - SCOPUS:85027956570
VL - 257
SP - 241
EP - 246
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
SN - 0257-8972
ER -