Achieving Ultra-Low Friction with Diamond/Metal Systems in Extreme Environments
In the search for achieving ultra-low friction for applications in extreme environments, we evaluate the interfacial processes of diamond/tungsten sliding contacts using an on-line macro-tribometer and a micro-tribometer in an ultra-high vacuum. The coefficient of friction for the tests with the on-...
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MDPI AG
2021-07-01
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| Online Access: | https://www.mdpi.com/1996-1944/14/14/3791 |
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| author | Pantcho Stoyanov Rolf Merz Markus Stricker Michael Kopnarski Martin Dienwiebel |
| author_facet | Pantcho Stoyanov Rolf Merz Markus Stricker Michael Kopnarski Martin Dienwiebel |
| author_sort | Pantcho Stoyanov |
| collection | DOAJ |
| description | In the search for achieving ultra-low friction for applications in extreme environments, we evaluate the interfacial processes of diamond/tungsten sliding contacts using an on-line macro-tribometer and a micro-tribometer in an ultra-high vacuum. The coefficient of friction for the tests with the on-line tribometer remained considerably low for unlubricated sliding of tungsten, which correlated well with the relatively low wear rates and low roughness on the wear track throughout the sliding. Ex situ analysis was performed by means of XPS and SEM-FIB in order to better understand the underlying mechanisms of low friction and low-wear sliding. The analysis did not reveal any evidence of tribofilm or transferfilm formation on the counterface, indicating the absence of significant bonding between the diamond and tungsten surfaces, which correlated well with the low-friction values. The minimal adhesive interaction and material transfer can possibly be explained by the low initial roughness values as well as high cohesive bonding energies of the two materials. The appearance of the wear track as well as the relatively higher roughness perpendicular to the sliding indicated that abrasion was the main wear mechanism. In order to elucidate the low friction of this tribocouple, we performed micro-tribological experiments in ultra-high vacuum conditions. The results show that the friction coefficient was reduced significantly in UHV. In addition, subsequently to baking the chamber, the coefficient of friction approached ultra-low values. Based on the results obtained in this study, the diamond/tungsten tribocouple seems promising for tribological interfaces in spacecraft systems, which can improve the durability of the components. |
| first_indexed | 2024-03-10T09:34:13Z |
| format | Article |
| id | doaj.art-41b0ebdb0f754cb4825f520f42bee622 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T09:34:13Z |
| publishDate | 2021-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-41b0ebdb0f754cb4825f520f42bee6222023-11-22T04:14:47ZengMDPI AGMaterials1996-19442021-07-011414379110.3390/ma14143791Achieving Ultra-Low Friction with Diamond/Metal Systems in Extreme EnvironmentsPantcho Stoyanov0Rolf Merz1Markus Stricker2Michael Kopnarski3Martin Dienwiebel4MicroTribology Center µTC, Fraunhofer-Institute for Mechanics of Materials IWM, Wöhlerstrasse 11, 79108 Freiburg, GermanyIFOS, “Institut für Oberflächen- und Schichtanalytik GmbH”, Trippstadter Straße 120, 67663 Kaiserslautern, GermanyInstitute for Applied Materials IAM, Karlsruhe Institute of Technology KIT, Kaiserstrasse 12, 76131 Karlsruhe, GermanyIFOS, “Institut für Oberflächen- und Schichtanalytik GmbH”, Trippstadter Straße 120, 67663 Kaiserslautern, GermanyMicroTribology Center µTC, Fraunhofer-Institute for Mechanics of Materials IWM, Wöhlerstrasse 11, 79108 Freiburg, GermanyIn the search for achieving ultra-low friction for applications in extreme environments, we evaluate the interfacial processes of diamond/tungsten sliding contacts using an on-line macro-tribometer and a micro-tribometer in an ultra-high vacuum. The coefficient of friction for the tests with the on-line tribometer remained considerably low for unlubricated sliding of tungsten, which correlated well with the relatively low wear rates and low roughness on the wear track throughout the sliding. Ex situ analysis was performed by means of XPS and SEM-FIB in order to better understand the underlying mechanisms of low friction and low-wear sliding. The analysis did not reveal any evidence of tribofilm or transferfilm formation on the counterface, indicating the absence of significant bonding between the diamond and tungsten surfaces, which correlated well with the low-friction values. The minimal adhesive interaction and material transfer can possibly be explained by the low initial roughness values as well as high cohesive bonding energies of the two materials. The appearance of the wear track as well as the relatively higher roughness perpendicular to the sliding indicated that abrasion was the main wear mechanism. In order to elucidate the low friction of this tribocouple, we performed micro-tribological experiments in ultra-high vacuum conditions. The results show that the friction coefficient was reduced significantly in UHV. In addition, subsequently to baking the chamber, the coefficient of friction approached ultra-low values. Based on the results obtained in this study, the diamond/tungsten tribocouple seems promising for tribological interfaces in spacecraft systems, which can improve the durability of the components.https://www.mdpi.com/1996-1944/14/14/3791space tribologyinterfacial phenomenadiamondtungstenthird-bodyXPS |
| spellingShingle | Pantcho Stoyanov Rolf Merz Markus Stricker Michael Kopnarski Martin Dienwiebel Achieving Ultra-Low Friction with Diamond/Metal Systems in Extreme Environments Materials space tribology interfacial phenomena diamond tungsten third-body XPS |
| title | Achieving Ultra-Low Friction with Diamond/Metal Systems in Extreme Environments |
| title_full | Achieving Ultra-Low Friction with Diamond/Metal Systems in Extreme Environments |
| title_fullStr | Achieving Ultra-Low Friction with Diamond/Metal Systems in Extreme Environments |
| title_full_unstemmed | Achieving Ultra-Low Friction with Diamond/Metal Systems in Extreme Environments |
| title_short | Achieving Ultra-Low Friction with Diamond/Metal Systems in Extreme Environments |
| title_sort | achieving ultra low friction with diamond metal systems in extreme environments |
| topic | space tribology interfacial phenomena diamond tungsten third-body XPS |
| url | https://www.mdpi.com/1996-1944/14/14/3791 |
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