Tribological Evaluation of Lead-Free MoS<sub>2</sub>-Based Solid Film Lubricants as Environmentally Friendly Replacements for Aerospace Applications
Solid lubricants, such as MoS<sub>2</sub> have been widely used in the aerospace industry with the primary purpose of reducing the friction and wear of tribological interfaces. MoS<sub>2</sub> based solid film lubricants are generally doped with other compounds, which can hel...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-01-01
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| Series: | Lubricants |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4442/10/1/7 |
| _version_ | 1797492635054637056 |
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| author | Parikshit Tonge Amit Roy Payank Patel Charles J. Beall Pantcho Stoyanov |
| author_facet | Parikshit Tonge Amit Roy Payank Patel Charles J. Beall Pantcho Stoyanov |
| author_sort | Parikshit Tonge |
| collection | DOAJ |
| description | Solid lubricants, such as MoS<sub>2</sub> have been widely used in the aerospace industry with the primary purpose of reducing the friction and wear of tribological interfaces. MoS<sub>2</sub> based solid film lubricants are generally doped with other compounds, which can help overcome some of their limitations related to environmental conditions. For instance, compounds like Sb<sub>2</sub>O<sub>3</sub> and Pb have been traditionally used to improve the endurance life of these lubricants. However, with the recent zest in transferring to eco-friendly lubricants, there is a strong push to eliminate Pb based compounds. The main purpose of this work is to better understand the influence of Pb based compounds on the tribological behavior of MoS<sub>2</sub> based solid film lubricants as well as to critically evaluate the performance of Pb free lubrication strategies. More specifically, the baseline ‘non-green’ lubricant was doped with Pb compound and Sb<sub>2</sub>O<sub>3</sub> and the Pb compound in the ‘Green’ alternative lubricant was replaced by more Sb<sub>2</sub>O<sub>3</sub>. The wear test was done using a ball-on-disk tribometer for specific loads and for 5000 cycles. Ex-situ analysis was conducted using Scanning Electron Microscope (SEM), Atomic Force Microscopy (AFM), and micro-Raman to capture the interfacial processes of these lubricants at different loads. Overall, the non-green lubricant performed better in terms of the tribological behavior (i.e., lower friction and wear), which was attributed to the formation of a dense MoS<sub>2</sub>-based tribo-/transfer-film with the basal planes oriented in the parallel direction to the sliding. The finding on the interfacial phenomena provided critical insights into the development of novel green alternatives that may have the ability to replace Pb based compounds in the future for a sustainable environment. |
| first_indexed | 2024-03-10T01:06:33Z |
| format | Article |
| id | doaj.art-851c4869acb44bde8aba7830eed8c4dd |
| institution | Directory Open Access Journal |
| issn | 2075-4442 |
| language | English |
| last_indexed | 2024-03-10T01:06:33Z |
| publishDate | 2022-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Lubricants |
| spelling | doaj.art-851c4869acb44bde8aba7830eed8c4dd2023-11-23T14:25:41ZengMDPI AGLubricants2075-44422022-01-01101710.3390/lubricants10010007Tribological Evaluation of Lead-Free MoS<sub>2</sub>-Based Solid Film Lubricants as Environmentally Friendly Replacements for Aerospace ApplicationsParikshit Tonge0Amit Roy1Payank Patel2Charles J. Beall3Pantcho Stoyanov4Department of Mechanical, Industrial and Aerospace Engineering, Concordia University, Montreal, QC H3G 1M8, CanadaDepartment of Mechanical, Industrial and Aerospace Engineering, Concordia University, Montreal, QC H3G 1M8, CanadaDepartment of Mechanical, Industrial and Aerospace Engineering, Concordia University, Montreal, QC H3G 1M8, CanadaEverlube Products, a Business Unit of Curtiss-Wright Corp., 100 Cooper Circle, Peachtree City, GA 30269, USADepartment of Chemical and Materials Engineering, Concordia University, Montreal, QC H3G 1M8, CanadaSolid lubricants, such as MoS<sub>2</sub> have been widely used in the aerospace industry with the primary purpose of reducing the friction and wear of tribological interfaces. MoS<sub>2</sub> based solid film lubricants are generally doped with other compounds, which can help overcome some of their limitations related to environmental conditions. For instance, compounds like Sb<sub>2</sub>O<sub>3</sub> and Pb have been traditionally used to improve the endurance life of these lubricants. However, with the recent zest in transferring to eco-friendly lubricants, there is a strong push to eliminate Pb based compounds. The main purpose of this work is to better understand the influence of Pb based compounds on the tribological behavior of MoS<sub>2</sub> based solid film lubricants as well as to critically evaluate the performance of Pb free lubrication strategies. More specifically, the baseline ‘non-green’ lubricant was doped with Pb compound and Sb<sub>2</sub>O<sub>3</sub> and the Pb compound in the ‘Green’ alternative lubricant was replaced by more Sb<sub>2</sub>O<sub>3</sub>. The wear test was done using a ball-on-disk tribometer for specific loads and for 5000 cycles. Ex-situ analysis was conducted using Scanning Electron Microscope (SEM), Atomic Force Microscopy (AFM), and micro-Raman to capture the interfacial processes of these lubricants at different loads. Overall, the non-green lubricant performed better in terms of the tribological behavior (i.e., lower friction and wear), which was attributed to the formation of a dense MoS<sub>2</sub>-based tribo-/transfer-film with the basal planes oriented in the parallel direction to the sliding. The finding on the interfacial phenomena provided critical insights into the development of novel green alternatives that may have the ability to replace Pb based compounds in the future for a sustainable environment.https://www.mdpi.com/2075-4442/10/1/7solid lubricantnon-greentribological behaviorinterfacial processestransfer-film |
| spellingShingle | Parikshit Tonge Amit Roy Payank Patel Charles J. Beall Pantcho Stoyanov Tribological Evaluation of Lead-Free MoS<sub>2</sub>-Based Solid Film Lubricants as Environmentally Friendly Replacements for Aerospace Applications Lubricants solid lubricant non-green tribological behavior interfacial processes transfer-film |
| title | Tribological Evaluation of Lead-Free MoS<sub>2</sub>-Based Solid Film Lubricants as Environmentally Friendly Replacements for Aerospace Applications |
| title_full | Tribological Evaluation of Lead-Free MoS<sub>2</sub>-Based Solid Film Lubricants as Environmentally Friendly Replacements for Aerospace Applications |
| title_fullStr | Tribological Evaluation of Lead-Free MoS<sub>2</sub>-Based Solid Film Lubricants as Environmentally Friendly Replacements for Aerospace Applications |
| title_full_unstemmed | Tribological Evaluation of Lead-Free MoS<sub>2</sub>-Based Solid Film Lubricants as Environmentally Friendly Replacements for Aerospace Applications |
| title_short | Tribological Evaluation of Lead-Free MoS<sub>2</sub>-Based Solid Film Lubricants as Environmentally Friendly Replacements for Aerospace Applications |
| title_sort | tribological evaluation of lead free mos sub 2 sub based solid film lubricants as environmentally friendly replacements for aerospace applications |
| topic | solid lubricant non-green tribological behavior interfacial processes transfer-film |
| url | https://www.mdpi.com/2075-4442/10/1/7 |
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