Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-22T21:55:15Z No. of bitstreams: 1 ErineiaDaSilvaSantos_DISSERT.pdf: 3035882 bytes, checksum: 42818d7e895e041fcfb6ca927e2d4834 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-02-24T00:26:37Z (GMT) No. of bitstreams: 1 ErineiaDaSilvaSantos_DISSERT.pdf: 3035882 bytes, checksum: 42818d7e895e041fcfb6ca927e2d4834 (MD5) / Made available in DSpace on 2016-02-24T00:26:37Z (GMT). No. of bitstreams: 1 ErineiaDaSilvaSantos_DISSERT.pdf: 3035882 bytes, checksum: 42818d7e895e041fcfb6ca927e2d4834 (MD5) Previous issue date: 2014-08-08 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Os fluidos de corte s?o lubrificantes usados no processo de usinagem nas ind?strias metalmec?nica por apresentarem v?rios benef?cios que variam de acordo com o tipo de opera??o executada. Estes fluidos s?o largamente utilizados como refrigeradores, como lubrificantes para melhorar o acabamento de superf?cies met?licas, reduzir o desgaste de ferramentas e proteg?-las contra a corros?o. Considerando as legisla??es vigentes e a demanda por produtos e processos considerados ?verdes?. Assim os ?leos vegetais representam uma solu??o para esses problemas, pois os ?leos vegetais aparecem como uma excelente alternativa para substitui??o do ?leos minerais. Deste modo, este trabalho teve como objetivo obter um fluido de corte emulsion?vel a base de ?leo vegetal epoxidado, para uma melhor lubrifica??o e refrigera??o no processo de usinagem, que n?o seja t?xico ao meio ambiente. O ?leo vegetal foi modificado quimicamente atrav?s da rea??o de epoxida??o com ?cido f?rmico. Foram determinadas as principais propriedades f?sico-qu?micas, tais como: densidade, acidez, ?ndice de iodo, ?ndice de oxirano, viscosidade, estabilidade t?rmica, al?m de caracteriza??es atrav?s de infravermelho e Resson?ncia Magn?tica Nuclear. O ?leo sintetizado foi utilizado para a formula??o das emuls?es O/A com diferentes concentra??es de ?leo epoxidado (10%, 20% e 25%) e com diferentes concentra??es de tensoativo (1%, 2,5% e 5%), e realizados estudos sobre a sua estabilidade. O desempenho tribol?gico das emuls?es O/A foi analisado pelo trib?metro HFRR (High Frequency Reciprocating Rig), que consiste num ensaio de desgaste do tipo esfera-plano. Os resultados mostraram que o biolubrificante pode ser sintetizado por rea??o de epoxida??o, os espectros, demonstraram que n?o houve 100% de convers?o das insatura??es em an?is ep?xi. Em rela??o ? avalia??o tribol?gica observa-se que o percentual de ?leo presente na emuls?o influenciou diretamente na forma??o de filme e coeficiente de atrito para maiores concentra??es o processo de forma??o de filme ? mais lento e inst?vel, bem como os valores de coeficiente de atrito. Maiores concentra??es de tensoativos n?o melhoraram o desempenho tribol?gico das emuls?es. O melhor desempenho para o processo de usinagem ? a emuls?o desenvolvida com 10% e 5% de tensoativo, a sua escara de desgaste em m?dia foi de WSD = 202?m. / The cutting fluids are lubricants used in machining processes, because they present many benefits for different processes. They have many functions, such as lubrication, cooling, improvement in surface finishing, besides they decreases the tool wear and protect it against corrosion. Therefore due to new environment laws and demand to green products, new cutting fluids must be development. These shall be biodegradable, non-toxic, safety for environment and operator healthy. Thus, vegetable oils are a good option to solve this problem, replacing the mineral oils. In this context, this work aimed to develop an emulsion cutting fluid from epoxidized vegetable oil, promoting better lubrication and cooling in machining processes, besides being environment friendly. The methodology was divided in five steps: first one was the biolubricant synthesis by epoxidation reaction. Following this, the biolubricant was characterized in terms of density, acidity, iodo index, oxirane index, viscosity, thermal stability and chemical composition. The third step was to develop an emulsion O/A with different oil concentration (10, 20 and 25%) and surfactant concentration (1, 2.5 and 5%). Also, emulsion stability was studied. The emulsion tribological performance were carried out in HFRR (High Frequency Reciprocating Rig), it consists in ball-disc contact. Results showed that the vegetable based lubricant may be synthesized by epoxidationreaction, the spectra showed that there was 100% conversion of the epoxy rings unsaturations. In regard the tribological assessment is observed that the percentage of oil present in the emulsion directly influenced the film formation and coefficient of friction for higher concentrations the film formation process is slow and unstable, and the coefficient of friction. The high concentrations of surfactants have not improved the emulsions tribological performance. The best performance in friction reduction was observed to emulsion with 10% of oil and 5% of surfactant, its average wear scar was 202 ?m.