Tribological Behavior of Reduced Graphene Oxide–Al<sub>2</sub>O<sub>3</sub> Nanofluid: Interaction among Testing Force, Rotational Speed and Nanoparticle Concentration
The tribological properties of nanofluids are influenced by multiple factors, and the interrelationships among the factors are deserving of further attention. In this paper, response surface methodology (RSM) was used to study the tribological behavior of reduced graphene oxide–Al<sub>2</su...
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MDPI AG
2022-07-01
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| Online Access: | https://www.mdpi.com/1996-1944/15/15/5177 |
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| author | Chenglong Wang Jianlin Sun Linghui Kong Jiaqi He |
| author_facet | Chenglong Wang Jianlin Sun Linghui Kong Jiaqi He |
| author_sort | Chenglong Wang |
| collection | DOAJ |
| description | The tribological properties of nanofluids are influenced by multiple factors, and the interrelationships among the factors are deserving of further attention. In this paper, response surface methodology (RSM) was used to study the tribological behavior of reduced graphene oxide–Al<sub>2</sub>O<sub>3</sub> (rGO-Al<sub>2</sub>O<sub>3</sub>) nanofluid. The interaction effects of testing force, rotational speed and nanoparticle concentration on the friction coefficient (<i>μ</i>), wear rate (<i>W</i><sub>r</sub>) and surface roughness (<i>R</i><sub>a</sub>) of steel disks were investigated via the analysis of variance. It was confirmed that all the three input variables were significant for <i>μ</i> and <i>W</i><sub>r</sub> values, while testing force, nanoparticle concentration and its interaction with testing force and rotational speed were identified as significant parameters for <i>R</i><sub>a</sub> value. According to regression quadratic models, the optimized response values were 0.088, 2.35 × 10<sup>−7</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup> and 0.832 μm for <i>μ</i>, <i>W</i><sub>r</sub> and <i>R</i><sub>a</sub>, which were in good agreement with the actual validation experiment values. The tribological results show that 0.20% was the optimum mass concentration which exhibited excellent lubrication performance. Compared to the base fluid, <i>μ</i>, <i>W</i><sub>r</sub> and <i>R</i><sub>a</sub> values had a reduction of approximately 45.6%, 90.3% and 56.0%. Tribochemical reactions occurred during the friction process, and a tribofilm with a thickness of approximately 20 nm was generated on the worn surface, consisting of nanoparticle fragments (rGO and Al<sub>2</sub>O<sub>3</sub>) and metal oxides (Fe<sub>2</sub>O<sub>3</sub> and FeO) with self-lubrication properties. |
| first_indexed | 2024-03-09T05:16:21Z |
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| id | doaj.art-ca0aa8555439498eb5d1508ec947f6e7 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T05:16:21Z |
| publishDate | 2022-07-01 |
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| spelling | doaj.art-ca0aa8555439498eb5d1508ec947f6e72023-12-03T12:45:05ZengMDPI AGMaterials1996-19442022-07-011515517710.3390/ma15155177Tribological Behavior of Reduced Graphene Oxide–Al<sub>2</sub>O<sub>3</sub> Nanofluid: Interaction among Testing Force, Rotational Speed and Nanoparticle ConcentrationChenglong Wang0Jianlin Sun1Linghui Kong2Jiaqi He3School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaSchool of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaThe Yellow River Institute of Hydraulic Research, the Yellow River Water Conservancy Commission, Zhengzhou 450003, ChinaSchool of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaThe tribological properties of nanofluids are influenced by multiple factors, and the interrelationships among the factors are deserving of further attention. In this paper, response surface methodology (RSM) was used to study the tribological behavior of reduced graphene oxide–Al<sub>2</sub>O<sub>3</sub> (rGO-Al<sub>2</sub>O<sub>3</sub>) nanofluid. The interaction effects of testing force, rotational speed and nanoparticle concentration on the friction coefficient (<i>μ</i>), wear rate (<i>W</i><sub>r</sub>) and surface roughness (<i>R</i><sub>a</sub>) of steel disks were investigated via the analysis of variance. It was confirmed that all the three input variables were significant for <i>μ</i> and <i>W</i><sub>r</sub> values, while testing force, nanoparticle concentration and its interaction with testing force and rotational speed were identified as significant parameters for <i>R</i><sub>a</sub> value. According to regression quadratic models, the optimized response values were 0.088, 2.35 × 10<sup>−7</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup> and 0.832 μm for <i>μ</i>, <i>W</i><sub>r</sub> and <i>R</i><sub>a</sub>, which were in good agreement with the actual validation experiment values. The tribological results show that 0.20% was the optimum mass concentration which exhibited excellent lubrication performance. Compared to the base fluid, <i>μ</i>, <i>W</i><sub>r</sub> and <i>R</i><sub>a</sub> values had a reduction of approximately 45.6%, 90.3% and 56.0%. Tribochemical reactions occurred during the friction process, and a tribofilm with a thickness of approximately 20 nm was generated on the worn surface, consisting of nanoparticle fragments (rGO and Al<sub>2</sub>O<sub>3</sub>) and metal oxides (Fe<sub>2</sub>O<sub>3</sub> and FeO) with self-lubrication properties.https://www.mdpi.com/1996-1944/15/15/5177reduced graphene oxidetribologynanofluidlubrication mechanismresponse surface methodology |
| spellingShingle | Chenglong Wang Jianlin Sun Linghui Kong Jiaqi He Tribological Behavior of Reduced Graphene Oxide–Al<sub>2</sub>O<sub>3</sub> Nanofluid: Interaction among Testing Force, Rotational Speed and Nanoparticle Concentration Materials reduced graphene oxide tribology nanofluid lubrication mechanism response surface methodology |
| title | Tribological Behavior of Reduced Graphene Oxide–Al<sub>2</sub>O<sub>3</sub> Nanofluid: Interaction among Testing Force, Rotational Speed and Nanoparticle Concentration |
| title_full | Tribological Behavior of Reduced Graphene Oxide–Al<sub>2</sub>O<sub>3</sub> Nanofluid: Interaction among Testing Force, Rotational Speed and Nanoparticle Concentration |
| title_fullStr | Tribological Behavior of Reduced Graphene Oxide–Al<sub>2</sub>O<sub>3</sub> Nanofluid: Interaction among Testing Force, Rotational Speed and Nanoparticle Concentration |
| title_full_unstemmed | Tribological Behavior of Reduced Graphene Oxide–Al<sub>2</sub>O<sub>3</sub> Nanofluid: Interaction among Testing Force, Rotational Speed and Nanoparticle Concentration |
| title_short | Tribological Behavior of Reduced Graphene Oxide–Al<sub>2</sub>O<sub>3</sub> Nanofluid: Interaction among Testing Force, Rotational Speed and Nanoparticle Concentration |
| title_sort | tribological behavior of reduced graphene oxide al sub 2 sub o sub 3 sub nanofluid interaction among testing force rotational speed and nanoparticle concentration |
| topic | reduced graphene oxide tribology nanofluid lubrication mechanism response surface methodology |
| url | https://www.mdpi.com/1996-1944/15/15/5177 |
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