Investigação da viabilidade de fluidos OLUC como alternativa aos fluidos de corte convencionais por meio de ensaios de desgaste em aço rápido

Nos processos de usinagem o desgaste das ferramentas é um processo inevitável que leva à necessidade de substitui-las, a fim de evitar danos à qualidade peça usinada, contribuindo para o custo total deste processo. A aplicação de fluidos de corte visa minimizar este desgaste durante a usinagem permitindo maiores velocidades de corte e/ou vida da ferramenta. Alguns fluidos de corte são a base de óleos minerais, contribuindo para as grandes quantidades de lubrificantes empregados pelas industrias nos componentes mecânicos. A produção, distribuição e descarte adequado de óleos lubrificantes envolvem custos significativos, além do prejuízo ambiental, pois o petróleo é um recurso natural. Óleos lubrificantes usados ou contaminados (OLUC) apresentam desafios ambientais significativos devido ao seu longo tempo de decomposição e ao potencial de contaminar a água e o solo se descartados inadequadamente. Esta pesquisa avalia a viabilidade da reutilização do OLUC como fluido de corte na usinagem, a fim de reduzir custos deste processo e contribuir para um menor impacto ao meio ambiente. Três ensaios de desgaste com tribômetro de esfera rotativa, girando a velocidade angular constante, foram realizados aplicando-se, em cada ensaio, fluido de corte convencional, OLUC mineral e OLUC sintético por meio de gotejamento destes elementos na região de contato entre a esfera e um bit de aço rápido tomado como corpo de prova (CDP). Para cada ensaio o CDP foi analisado em um microscópio óptico para medir o diâmetro da calota esférica gerada pelo desgaste para percursos de deslizamento da esfera sobre o bit de 1000, 2000, 3000, 4000 e 5000 metros. As medidas dos diâmetros das calotas geradas revelaram um comportamento de desgaste semelhante entre os três fluidos. Para percurso de 1000 metros, as taxas de desgaste foram: 6,91 x 10⁻⁷ mm³/m para fluido de corte, 5,72 x 10⁻⁷ mm³/m para óleo mineral e 3,29 x 10⁻⁷ mm³/m para óleo sintético. Para distâncias de 1000, 2000 ,3000 e 4000 metros o OLUC sintético e mineral mostraram taxas menores que o fluido de corte convencional. Para distância de 5000 m o fluido convencional mostrou uma taxa de desgaste menor (4,44 x 10⁻⁷ mm³/m), o óleo sintético teve uma taxa de desgaste maior (5,08 x 10⁻⁷ mm³/m) do que sua taxa inicial, e o óleo mineral apresentou a maior taxa de desgaste (7,74 x 10⁻⁷ mm³/m). Para processos de usinagem em que o atrito é a principal causa do desgaste, os óleos lubrificantes usados podem reduzir efetivamente o desgaste da ferramenta. No entanto, para usinagem de alta velocidade em que a temperatura é o principal fator, o fluido de corte convencional continua sendo a melhor opção. Verifica-se assim, o potencial de utilização do OLUC como uma alternativa sustentável em condições específicas de usinagem, contribuindo tanto para a economia deste processo, quanto para a proteção ambiental. A utilização do OLUC, como fluido de corte mostra-se viável para distâncias de ensaio de desgaste até 3000 metros, a partir disso, ocorrem fenômenos, os quais causam o aumento da taxa de desgaste superior aos ensaios de desgaste com a utilização do fluido de corte convencional.

Resumo (inglês)

In machining processes, tool wear is inevitable, necessitating tool replacement to avoid compromising the quality of the machined part and adding to the process’s total cost. The application of cutting fluids aims to minimize this wear, enabling higher cutting speeds and/or extended tool life. Some cutting fluids are mineral oil-based, contributing to the vast quantities of lubricants used by industries for mechanical components. The production, distribution, and proper disposal of lubricating oils entail significant costs and environmental damage, given that petroleum is a natural resource. Used or contaminated lubricating oils (OLUC) pose significant environmental challenges due to their long decomposition times and potential to contaminate water and soil if disposed of improperly. This research evaluates the feasibility of reusing OLUC as a cutting fluid in machining to reduce process costs and minimize environmental impact. Three wear tests were conducted using a rotating-ball tribometer operating at a constant angular velocity; in each test, a conventional cutting fluid, mineral OLUC, and synthetic OLUC were applied via dripping at the contact point between the ball and a high-speed steel bit (the test specimen). Following each test, the specimen was examined under an optical microscope to measure the diameter of the wear scar (spherical cap) produced over sliding distances of 1,000, 2,000, 3,000, 4,000, and 5,000 meters. Measurements of the resulting wear scar diameters revealed similar wear behavior across the three fluids. For a 1,000-meter run, the wear rates were: 6.91 × 10−7 mm³/m for cutting fluid, 5.72 × 10−7 mm³/m for mineral oil, and 3.29 × 10−7 mm³/m for synthetic oil. For distances of 1,000, 2,000, 3,000, and 4,000 meters, the synthetic and mineral OLUCs showed lower rates than the conventional cutting fluid. At a distance of 5,000 m, the conventional fluid showed a lower wear rate (4.44 × 10−7 mm³/m), the synthetic oil had a higher wear rate (5.08 × 10−7 mm³/m) than its initial rate, and the mineral oil exhibited the highest wear rate (7.74 × 10−7 mm³/m). For machining processes where friction is the primary cause of wear, used lubricating oils can effectively reduce tool wear. However, for high-speed machining where temperature is the main factor, conventional cutting fluid remains the best option. Thus, the potential for using OLUC as a sustainable alternative under specific machining conditions is evident, contributing to both the process’s economics and environmental protection. The use of OLUC as a cutting fluid proves viable for wear test distances of up to 3,000 meters; beyond this point, phenomena occur that cause the wear rate to rise above that observed in tests using conventional cutting fluid.In machining processes, tool wear is inevitable, necessitating tool replacement to avoid compromising the quality of the machined part and adding to the process’s total cost. The application of cutting fluids aims to minimize this wear, enabling higher cutting speeds and/or extended tool life. Some cutting fluids are mineral oil-based, contributing to the vast quantities of lubricants used by industries for mechanical components. The production, distribution, and proper disposal of lubricating oils entail significant costs and environmental damage, given that petroleum is a natural resource. Used or contaminated lubricating oils (OLUC) pose significant environmental challenges due to their long decomposition times and potential to contaminate water and soil if disposed of improperly. This research evaluates the feasibility of reusing OLUC as a cutting fluid in machining to reduce process costs and minimize environmental impact. Three wear tests were conducted using a rotating-ball tribometer operating at a constant angular velocity; in each test, a conventional cutting fluid, mineral OLUC, and synthetic OLUC were applied via dripping at the contact point between the ball and a high-speed steel bit (the test specimen). Following each test, the specimen was examined under an optical microscope to measure the diameter of the wear scar (spherical cap) produced over sliding distances of 1,000, 2,000, 3,000, 4,000, and 5,000 meters. Measurements of the resulting wear scar diameters revealed similar wear behavior across the three fluids. For a 1,000-meter run, the wear rates were: 6.91 × 10−7 mm³/m for cutting fluid, 5.72 × 10−7 mm³/m for mineral oil, and 3.29 × 10−7 mm³/m for synthetic oil. For distances of 1,000, 2,000, 3,000, and 4,000 meters, the synthetic and mineral OLUCs showed lower rates than the conventional cutting fluid. At a distance of 5,000 m, the conventional fluid showed a lower wear rate (4.44 × 10−7 mm³/m), the synthetic oil had a higher wear rate (5.08 × 10−7 mm³/m) than its initial rate, and the mineral oil exhibited the highest wear rate (7.74 × 10−7 mm³/m). For machining processes where friction is the primary cause of wear, used lubricating oils can effectively reduce tool wear. However, for high-speed machining where temperature is the main factor, conventional cutting fluid remains the best option. Thus, the potential for using OLUC as a sustainable alternative under specific machining conditions is evident, contributing to both the process’s economics and environmental protection. The use of OLUC as a cutting fluid proves viable for wear test distances of up to 3,000 meters; beyond this point, phenomena occur that cause the wear rate to rise above that observed in tests using conventional cutting fluid.

Palavras-chave

Ensaio de desgaste Aço rápido Esfera rotativa Óleo lubrificante Fluido de corte OLUC

Idioma

Português

Citação

NUNES, Elias do Amaral. Investigação da viabilidade de fluidos oluc como alternativa aos fluidos de corte convencionais por meio de ensaios de desgaste em aço rápido. Orientador: Wyser José Yamakami. 2026. Trabalho de conclusão de curso (Graduação em Engenharia Mecânica) - Universidade Estadual Paulista (UNESP), Faculdade de Engenharia, Ilha Solteira, 2026