Sustentabilidade industrial combinado com conceitos de mitigação de efeito estufa aplicado ao processo de retificação
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Data
2023-08-04
Autores
Carvalho, Guilherme Antônio
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A retificação é um processo de usinagem aplicado em diversas indústrias, aplicada na fabricação de peças que necessitam um excelente acabamento superficial, ou superfícies com alta precisão geométrica. Desse modo, qualquer erro durante a usinagem gera um grande prejuízo, pois invalida os processos anteriores à retificação. Por conta disso, o estudo sobre esse processo, sob diversos cenários, é necessário, a fim de otimiza-lo. Com o avanço da engenharia dos materiais, novos elementos estão sendo usados como matéria-prima na indústria, as cerâmicas é um desses materiais, por conta de sua estabilidade química e térmica, associada a uma alta durabilidade, a sua aplicação em caldeiras e válvulas vem aumentando. Entretanto, essas mesmas qualidades que possibilitam sua utilização, dificultam sua usinagem, principalmente pelas altas temperaturas durante o processo. A fim de reduzir esse problema, novos métodos de lubrirrefrigeração vem sendo estudados, em conjunto com esses materiais. Nesse trabalho, será estudado o comportamento de peças anelares de óxido de alumínio, retificadas com rebolos de diamante sintético. Para o controle da temperatura, a performance de três métodos de refrigeração será estudada, sendo eles o método com fluido em abundância, mínima quantidade de lubrificação (MQL) e MQL associado com a limpeza do rebolo (WCJ) (MQL+WCJ), aplicado em diferentes angulações (0°, 30°,60° e 90°). Para avaliar a performance da usinagem, parâmetros como a rugosidade (Ra), desvio de circularidade, desgaste diametral do rebolo, razão G, potência de retificação, força tangencial e uma análise dos custos e poluição envolvendo cada aplicação também foram feitos. Ao final, o método convencional de lubrificação flood apresentou a melhor performance para o acabamento superficial e desvio de circularidade, entretanto, o método de MQL+WCJ, com um ângulo de 30° apresentou resultados próximos, se mostrando competitivo. As aplicações de MQL apresentaram baixos valores de poluição, quando comparados ao método convencional, sendo assim uma ótima alternativa verde para esse sistema de lubrificação.
Grinding is a machining process applied in the manufacture of components that require an excellent surface finish and high geometric and dimensional precision, being applied in the final stages of component manufacturing. Due to its high heat generation, grinding needs adequate lubrication and cooling methods, aiming to meet the demands of the ground component as well as to mitigate the environmental impacts resulting from the application of cutting fluids. Allied with this, the growing demand for new materials, such as advanced ceramics, has become a new challenge for grinding. In addition to being chemically and thermally stable, advanced ceramics are highly resistant to wear, making grinding this type of material difficult. Traditionally, cutting fluids have alkanolamines, nitrosamines, volatile organic compounds, mineral oils, hydrocarbons and heavy metals in their composition. Thus requiring proper disposal to inhibit groundwater and soil contamination, reducing immediate and long-term damage to the planet and society. That said, it is extremely important that scientific and technological advances in machining processes, especially grinding, allow for cleaner machining through techniques that reduce the need to apply large volumes of cutting fluid. In this sense, the minimum quantity lubrication technique (MQL) consists of applying a small amount of oil through a jet of compressed air, achieving results similar to the flood method in many cases. However, the lower cooling capacity of MQL is an obstacle to overcome. Thus, this work analyzed advanced grinding ceramics using a diamond grinding wheel combined with a new technology responsible for cleaning the grinding wheel (WCJ) under four different angles (0◦, 30◦, 60◦ and 90◦). Surface roughness, roundness error, diametral wear of the grinding wheel, G ratio, grinding power, grinding cost analysis, and pollutant CO2 emissions involving each application were evaluated. As a result, the flood lubrirrefrigeration method showed the best performance in roughness and surface roundness error values. However, the MQL + WCJ 30◦ presented similar results about the flooding method, proving competitive for industrial use. Furthermore, MQL applications led to lower CO2 pollution values than the flood method, making it a great green alternative for the environment.
Grinding is a machining process applied in the manufacture of components that require an excellent surface finish and high geometric and dimensional precision, being applied in the final stages of component manufacturing. Due to its high heat generation, grinding needs adequate lubrication and cooling methods, aiming to meet the demands of the ground component as well as to mitigate the environmental impacts resulting from the application of cutting fluids. Allied with this, the growing demand for new materials, such as advanced ceramics, has become a new challenge for grinding. In addition to being chemically and thermally stable, advanced ceramics are highly resistant to wear, making grinding this type of material difficult. Traditionally, cutting fluids have alkanolamines, nitrosamines, volatile organic compounds, mineral oils, hydrocarbons and heavy metals in their composition. Thus requiring proper disposal to inhibit groundwater and soil contamination, reducing immediate and long-term damage to the planet and society. That said, it is extremely important that scientific and technological advances in machining processes, especially grinding, allow for cleaner machining through techniques that reduce the need to apply large volumes of cutting fluid. In this sense, the minimum quantity lubrication technique (MQL) consists of applying a small amount of oil through a jet of compressed air, achieving results similar to the flood method in many cases. However, the lower cooling capacity of MQL is an obstacle to overcome. Thus, this work analyzed advanced grinding ceramics using a diamond grinding wheel combined with a new technology responsible for cleaning the grinding wheel (WCJ) under four different angles (0◦, 30◦, 60◦ and 90◦). Surface roughness, roundness error, diametral wear of the grinding wheel, G ratio, grinding power, grinding cost analysis, and pollutant CO2 emissions involving each application were evaluated. As a result, the flood lubrirrefrigeration method showed the best performance in roughness and surface roundness error values. However, the MQL + WCJ 30◦ presented similar results about the flooding method, proving competitive for industrial use. Furthermore, MQL applications led to lower CO2 pollution values than the flood method, making it a great green alternative for the environment.
Descrição
Palavras-chave
Retificação, Cerâmica avançada, Mínima Quantidade de Lubrificante (MQL), Rebolo de diamante, WCJ, Grinding, Advanced ceramic, Diamond grinding wheel