Tribological performances of halogen-free ionic liquids against a-C:H and ta-C films under vacuum
Ionic liquids have high potential as novel lubricants because of their unique physical properties. In particular, halogen-free ionic liquids are low environmental-load lubricants. Unfortunately, these ionic liquids exhibit a poor tribological performance against bearing steel. However, they exhibit...
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2020-03-01
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| Series: | Journal of Advanced Mechanical Design, Systems, and Manufacturing |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/jamdsm/14/3/14_2020jamdsm0032/_pdf/-char/en |
| _version_ | 1818532706269528064 |
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| author | Shouhei KAWADA Shinya SASAKI Masaaki MIYATAKE |
| author_facet | Shouhei KAWADA Shinya SASAKI Masaaki MIYATAKE |
| author_sort | Shouhei KAWADA |
| collection | DOAJ |
| description | Ionic liquids have high potential as novel lubricants because of their unique physical properties. In particular, halogen-free ionic liquids are low environmental-load lubricants. Unfortunately, these ionic liquids exhibit a poor tribological performance against bearing steel. However, they exhibit high performances against diamond-like carbon (DLC) under the high vacuum condition. The influence of DLC species on tribological performances and the reaction mechanism of halogen-free ionic liquids on the worn surface are still unknown. This investigation evaluates the tribological performances of halogen-free ionic liquids (1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCN]), 1-ethyl-3-methylimidazolium tricyanomethane ([EMIM][TCC]), and 1-ethyl-3-methylimidazolium tetracyanoborate ([EMIM][TCB])) against two types of DLC (tetrahedral amorphous carbon (ta-C) and hydrogenated amorphous carbon (a-C:H)). The tribological performances of ionic liquids differed by the anion structure and the type of DLCs. The DLCs lubricated with [EMIM][DCN] and ta-C lubricated with [EMIM][TCC] exhibited a low friction coefficient. On the other hand, other ionic liquids exhibited the high friction coefficients against DLCs. A time-of-flight secondary-ion mass spectrometer analysis indicated that the tribo-decomposition of halogen-free ionic liquids and the adsorption of anion achieve a low friction. The chemical activity of nascent surfaces plays a very important role in achieving tribo-decomposition. However, because this activity of DLC was lower than that of bearing steel, [EMIM][TCC] exhibited a poor tribological performance. Thus, although the tribological performances of halogen-free ionic liquids can be improved by using DLC as sliding materials, there is also the possibility of inhibiting the formation of an adsorption layer derived from ionic liquids. |
| first_indexed | 2024-12-11T17:49:02Z |
| format | Article |
| id | doaj.art-3f80f39a294f46ab93b0db7013bbc031 |
| institution | Directory Open Access Journal |
| issn | 1881-3054 |
| language | English |
| last_indexed | 2024-12-11T17:49:02Z |
| publishDate | 2020-03-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Journal of Advanced Mechanical Design, Systems, and Manufacturing |
| spelling | doaj.art-3f80f39a294f46ab93b0db7013bbc0312022-12-22T00:56:17ZengThe Japan Society of Mechanical EngineersJournal of Advanced Mechanical Design, Systems, and Manufacturing1881-30542020-03-01143JAMDSM0032JAMDSM003210.1299/jamdsm.2020jamdsm0032jamdsmTribological performances of halogen-free ionic liquids against a-C:H and ta-C films under vacuumShouhei KAWADA0Shinya SASAKI1Masaaki MIYATAKE2Tokyo University of ScienceTokyo University of ScienceTokyo University of ScienceIonic liquids have high potential as novel lubricants because of their unique physical properties. In particular, halogen-free ionic liquids are low environmental-load lubricants. Unfortunately, these ionic liquids exhibit a poor tribological performance against bearing steel. However, they exhibit high performances against diamond-like carbon (DLC) under the high vacuum condition. The influence of DLC species on tribological performances and the reaction mechanism of halogen-free ionic liquids on the worn surface are still unknown. This investigation evaluates the tribological performances of halogen-free ionic liquids (1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCN]), 1-ethyl-3-methylimidazolium tricyanomethane ([EMIM][TCC]), and 1-ethyl-3-methylimidazolium tetracyanoborate ([EMIM][TCB])) against two types of DLC (tetrahedral amorphous carbon (ta-C) and hydrogenated amorphous carbon (a-C:H)). The tribological performances of ionic liquids differed by the anion structure and the type of DLCs. The DLCs lubricated with [EMIM][DCN] and ta-C lubricated with [EMIM][TCC] exhibited a low friction coefficient. On the other hand, other ionic liquids exhibited the high friction coefficients against DLCs. A time-of-flight secondary-ion mass spectrometer analysis indicated that the tribo-decomposition of halogen-free ionic liquids and the adsorption of anion achieve a low friction. The chemical activity of nascent surfaces plays a very important role in achieving tribo-decomposition. However, because this activity of DLC was lower than that of bearing steel, [EMIM][TCC] exhibited a poor tribological performance. Thus, although the tribological performances of halogen-free ionic liquids can be improved by using DLC as sliding materials, there is also the possibility of inhibiting the formation of an adsorption layer derived from ionic liquids.https://www.jstage.jst.go.jp/article/jamdsm/14/3/14_2020jamdsm0032/_pdf/-char/entribologyionic liquidsdiamond-like carbonvacuumtof-sims |
| spellingShingle | Shouhei KAWADA Shinya SASAKI Masaaki MIYATAKE Tribological performances of halogen-free ionic liquids against a-C:H and ta-C films under vacuum Journal of Advanced Mechanical Design, Systems, and Manufacturing tribology ionic liquids diamond-like carbon vacuum tof-sims |
| title | Tribological performances of halogen-free ionic liquids against a-C:H and ta-C films under vacuum |
| title_full | Tribological performances of halogen-free ionic liquids against a-C:H and ta-C films under vacuum |
| title_fullStr | Tribological performances of halogen-free ionic liquids against a-C:H and ta-C films under vacuum |
| title_full_unstemmed | Tribological performances of halogen-free ionic liquids against a-C:H and ta-C films under vacuum |
| title_short | Tribological performances of halogen-free ionic liquids against a-C:H and ta-C films under vacuum |
| title_sort | tribological performances of halogen free ionic liquids against a c h and ta c films under vacuum |
| topic | tribology ionic liquids diamond-like carbon vacuum tof-sims |
| url | https://www.jstage.jst.go.jp/article/jamdsm/14/3/14_2020jamdsm0032/_pdf/-char/en |
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