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Previous issue date: 2017-09-29 / O Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Engrenagens e outros conjuntos mec?nicos s?o muito importantes para a convers?o da energia e?lica em energia el?trica em turbinas e?licas, mas a sua durabilidade e efici?ncia s?o severamente prejudicadas por algumas quest?es tribol?gicas como corros?o, desgaste, deforma??o e fragmenta??o. Os lubrificantes utilizados para reduzir esse desgaste e deforma??o s?o de fontes n?o renov?veis podendo n?o ser vi?veis ambientalmente. Assim, surgem novas tecnologias que visam o desenvolvimento de produtos de fontes renov?veis substituindo o ?leo mineral e aditivo de extrema press?o. A este respeito, ?leos vegetais e novos aditivos inorg?nicos est?o sendo pesquisados como uma alternativa adequada para substituir os lubrificantes utilizados atualmente em engrenagens de turbinas e?licas. O objetivo desse trabalho foi sintetizar nanopart?culas est?veis inorg?nicas em ?leos vegetais por sputtering, desenvolvendo lubrificantes mais adaptados ao meio ambiente com aditivos mais eficientes. A metodologia aplicada est? divida em 5 etapas: 1- prepara??o do biolubrificante (?leo de girassol epoxidado); 2- caracteriza??o f?sico-quimica dos lubrificantes; 3- deposi??o das nanopart?culas por sputtering; 4- caracteriza??o da dispers?o e 5 avalia??o tribol?gica. Nas deposi??es foram utilizados tr?s n?veis de corrente de descarga e taxa de deposi??o (30 mA- 0,8 ?/s, 40 mA- 1,3 ?/s e 50 mA- 1,51 ?/s), tr?s diferentes concentra??es, em peso, de nanopart?culas (0,05%, 0,1% e 0,3%) e com alvo Cu para se obter nanopart?culas de cobre. As nanopart?culas formadas foram caracterizadas em fun??o do tamanho de part?cula pela t?cnica de SAXS e por MEV. A dispers?o das nanopart?culas foi analisada por Uv-Vis?vel, Polidispersividade, Potencial Zeta e SAXS. Para avaliar o desempenho tribol?gico foi utilizado o trib?metro HFRR. Os resultados mostraram que os biolubrificantes com melhoram o desempenho tribol?gico melhorando o desgaste e reduzindo atrito em superf?cies met?licas. Al?m disso, este m?todo de preparo do nanobiolubrificante eliminou o problema de dispers?o verificado por outras t?cnicas de dispers?o. / Gears and other mechanical assemblies are very important for the conversion of wind energy into electrical energy in wind turbines, but their durability and efficiency are severely hampered by some tribological issues such as corrosion, wear, deformation and fragmentation. The lubricants used to reduce this wear and deformation is from non-renewable sources and may not be environmentally viable. Thus, new technologies appear that aim at the development of renewable products replacing mineral oil and extreme pressure additive. In this regard, vegetable oils and new inorganic additives are being researched as a suitable alternative to replace the lubricants currently used in wind turbine gears. The objective of this work is to synthesize inorganic nanoparticles in vegetable oils by sputtering to obtain stable colloidal nanoparticles (NPs), developing lubricants more adapted to the environment with more efficient additives, with a better level of tribological performance. The applied methodology is divided in 5 steps: 1- preparation of the biolubrificante (epoxidized sunflower oil); 2- physico-chemical characterization of the lubricants; 3- deposition of the nanoparticles by sputtering; 4 - characterization of the dispersion and 5 tribological evaluations. In the depositions three discharge current levels (30 mA- 0.8 ? / s, 40 mA- 1.3 ? / s and 50 mA- 1.51 ? / s) and three deposition rates were used to obtain three different concentrations by weight of nanoparticles (0,05%, 0,1 % and 0,3%) and with Cu target to obtain copper nanoparticles. The nanoparticle formed was characterized as a function of the particle size by the SAXS technique and a sample by SEM. The dispersion of the nanoparticles was analyzed by Uv-Visible, Polydispersivity, Zeta Potential and SAXS. To evaluate the tribological performance was used the HFRR trbometer. The results showed that the biolubrificants with additives had good performace, improved wear and reduced friction on metal surfaces. In addition, this method of preparing the nanobiolubrifier eliminated the dispersion problem ascertained by other dispersion techniques.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/24938 |
| Date | 29 September 2017 |
| Creators | Trajano, Marinalva Ferreira |
| Contributors | 02046752945, Franceschini Filho, Dante Ferreira, 53549287704, Bohn, Felipe, 99793628049, Silva, Fl?vio Jos? da, 88244350415, Nascimento, Jos? Heriberto Oliveira do, 02452573493, Alves, Salete Martins |
| Publisher | PROGRAMA DE P?S-GRADUA??O EM ENGENHARIA MEC?NICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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