Análise do desempenho de diferentes fluidos de corte aplicados na técnica de MQL na retificação cilíndrica de mergulho do aço AISI 4340 com rebolo de CBN
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Data
2019-07-26
Autores
Saes, Saulo Aguiar
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Universidade Estadual Paulista (Unesp)
Resumo
Com o desenvolvimento da indústria metal-mecânica e a crescente demanda por formas mais ecológicas de utilização e manutenção dos recursos naturais, tem-se a meta de utilizar e gerar menos resíduos que sejam nocivos ao meio-ambiente, bem como aos seres humanos. Isso se aplica aos processos de usinagem, nos quais se procuram por fontes alternativas de lubrificação, as quais reduzam os malefícios gerados ao ecossistema. Seguindo essa vertente tem-se a técnica de mínima quantidade de lubrificação - MQL, a qual preza por uma maior eficiência do processo ao utilizar menos fluido se comparada com o uso de líquidos refrigerantes em abundância. Porém, a utilização de MQL demanda certos cuidados no que se refere à limpeza da zona de corte, e às trocas de calor do sistema ferramenta-peça. Portanto, o presente trabalho analisou o comportamento da técnica de MQL associada à limpeza, onde foram utilizados três tipos de fluidos: Rocol Biocut 9000 fluido próprio para a aplicação na técnica de MQL, Quimatic Tapmatic ME-2: fluido sintético, normalmente utilizado na refrigeração convencional, mas que tende a ter resultados bons na utilização em MQL e um terceiro fluido VCI Aqua 180: fluido com propriedades anticorrosivas e com inibidor de empastamento. Todos os fluidos foram diluídos nas proporções 1:5 ou seja uma parte de óleo e cinco partes de água (83% de diluição em agua), 1:10 ou seja uma parte de óleo e dez partes de água (90,90% de diluição em agua) além do óleo puro. Dessa forma, foram analisadas variáveis de saída do processo, sendo a rugosidade, desvios de circularidade, relação G (volume de material removido/ volume de rebolo desgastado), microdureza, microscopia óptica da superfície da peça, potência elétrica consumida, emissão acústica e vibração. Os resultados dos estudos demonstraram que, a adição de água contribuiu positivamente para os valores de rugosidade em todos os fluidos de corte testados. Além disso, observou-se que a técnica de MQL aliada com o sistema de limpeza com ar comprimido da superfície de corte do rebolo, obteve resultados compatíveis com a rugosidade provida pela refrigeração convencional, de modo geral todos os parâmetros analisados proporcionaram um desempenho superior com adição de água, pelo maior efeito refrigerante promovido pela técnica.
With the development of the metal-mechanic industry and the growing demand for more ecological ways of using and maintaining natural resources, the goal is to use and generate less waste that is harmful to the environment as well as to humans. This applies to machining processes in which alternative sources of lubrication are sought, which reduce the damage to the ecosystem. Following this strand is the technique of minimum amount of lubrication - MQL, which values a greater efficiency of the process when using less fluid when compared with the use of abundant soft liquids. However, the use of MQL requires certain care regarding the cleaning of the cutting zone, and the heat exchanges of the tool-part system. Therefore, the present work analyzed the behavior of the MQL technique associated to cleaning, where three types of fluids were used: Rocol Biocut 9000 suitable for the application in the MQL technique, Quimatic Tapmatic ME-2: synthetic fluid, normally used in refrigeration conventional but which tends to have good results in the use in MQL and a third VCI Aqua 180 fluid: fluid with anticorrosive properties and with impasto inhibitor. All the fluids were diluted 1: 5 in either one part oil and five parts water (83% dilution in water), 1:10 or one part oil and ten parts water (90.90% dilution in water) plus pure oil. In this way, process output variables were analyzed, such as roughness, circularity deviation, G ratio (volume of removed material / volume of worn grinding wheel), microhardness, optical microscopy of the workpiece surface, electric power consumed, acoustic emission and vibration . The results of the studies showed that the addition of water contributed positively to the roughness values in all the cutting fluids tested. Furthermore, it was observed that the MQL technique combined with the grinding surface compressed air cleaning system, obtained results compatible with the roughness provided by conventional cooling, in general all the parameters analyzed provided a superior performance with addition of water, due to the greater cooling effect promoted by the technique.
With the development of the metal-mechanic industry and the growing demand for more ecological ways of using and maintaining natural resources, the goal is to use and generate less waste that is harmful to the environment as well as to humans. This applies to machining processes in which alternative sources of lubrication are sought, which reduce the damage to the ecosystem. Following this strand is the technique of minimum amount of lubrication - MQL, which values a greater efficiency of the process when using less fluid when compared with the use of abundant soft liquids. However, the use of MQL requires certain care regarding the cleaning of the cutting zone, and the heat exchanges of the tool-part system. Therefore, the present work analyzed the behavior of the MQL technique associated to cleaning, where three types of fluids were used: Rocol Biocut 9000 suitable for the application in the MQL technique, Quimatic Tapmatic ME-2: synthetic fluid, normally used in refrigeration conventional but which tends to have good results in the use in MQL and a third VCI Aqua 180 fluid: fluid with anticorrosive properties and with impasto inhibitor. All the fluids were diluted 1: 5 in either one part oil and five parts water (83% dilution in water), 1:10 or one part oil and ten parts water (90.90% dilution in water) plus pure oil. In this way, process output variables were analyzed, such as roughness, circularity deviation, G ratio (volume of removed material / volume of worn grinding wheel), microhardness, optical microscopy of the workpiece surface, electric power consumed, acoustic emission and vibration . The results of the studies showed that the addition of water contributed positively to the roughness values in all the cutting fluids tested. Furthermore, it was observed that the MQL technique combined with the grinding surface compressed air cleaning system, obtained results compatible with the roughness provided by conventional cooling, in general all the parameters analyzed provided a superior performance with addition of water, due to the greater cooling effect promoted by the technique.
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Palavras-chave
Retificação cilíndrica externa, Mínima quantidade de lubrificante (MQL), Aço AISI 4340, Rebolo de CBN, External cylindrical grinding, Minimum quantity of lubricant (MQL), AISI 4340 steel, CBN grinding wheel