Otimização da retificação tangencial plana de compósitos plásticos reforçados com fibras de carbono
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Data
2011-02-10
Autores
Varasquim, Francisco Mateus Faria de Almeida [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Os materiais compósitos estão se tornando essenciais e amplamente utilizados na indústria moderna, principalmente nas indústrias aeronáuticas e aeroespacial. Essa notável demanda por este tipo de material, proveniente da junção entre dois ou mais materiais distintos, pode ser explicada pelo resultado alcançado com essa combinação: propriedades específicas e otimizadas para cada aplicação. Devido à anisotropia do material, há a tendência de aparecimento de tensões residuais ou distorções estruturais, após o seu processamento. Para o devido controle destas distorções, é imperativo o processo de usinagem denominado retificação. Nesse processo de usinagem, há a necessidade da utilização de grande quantidade de fluido de corte (refrigeração convencional). Referente a preocupações ambientais, surgem métodos que visam reduzir a utilização abundante de fluidos de corte, como: a refrigeração otimizada, a técnica de mínima quantidade de lubrificação (MQL) e a retificação a seco. O presente trabalho analisou os métodos de lubri-refrigeração citados, na retificação plana de compósitos plásticos reforçados com fibras de carbono (PRFC'S), como alternativas à retificação convencional, buscando mitigar o uso de fluidos de corte no meio industrial. Essa análise através da coleta de dados sobre a eficiência do processo e a qualidade superficial das peças, através das seguintes variáveis de saída: o comportamento de força tangencial de corte, rugosidade, energia específica, relação G (volume de material removido/volume de rebolo desgastado) e microscopia eletrônica de varredura (MEV). Com os resultados obtidos, verificou-se que a técnica de MQL gerou valores mais baixos de força tangencial de corte e energia específica de retificação. Já os métodos convencional e otimizado proporcionaram um menor desgaste da ferramenta de corte, bem como um melhor acabamento superficial
Composite materials are becoming essential and largely used in modern industry, mainly is aeronautics and aerospace industries. This notable demand for these materials, generated from the combination of two or more distinct materials, can be explained by some results obtained: unique and optimized properties specific for each application. One of the main reasons for its large use it is their structural composition, which comes from the fusion of two different materials, resulting into excellent structural properties. Due to the material anisotropy, there is a trend of appering residual stresses and structural distortions, after its processing. For the adequade control of these distortions, it is necessary a machining process called grinding. When grinding these materials, there is a need of a great quantity of cutting fluids (conventional lubrication). In relation to the environmental concerns, new methodologies arise, which intend to reduce this large quantity of cutting fluid, like optimized cooling, the minimum quantity lubrification (MQL) technique and dry grinding. The present work analyzed the aforementioned lubri-cooling methods, on surface grinding of carbon fiber reinforced plastic composities (CFRP's), as alternatives to conventional cooling, in order to mitigate the deleterious effects of cutting fluids. This analysis was conducted through data gathering concerning the process efficiency and the the workpiece surface quality, using the following output variables: bahavior of the tangential force, surface roughness, specific grinding energy, G relation and scanning electron microscopy (SEM). With the results obtained, it can be verified that the MQL technique generated the lowest values of tangential cutting force and griding specific energy. The optimized and conventional methods provided the lowest wear of the grinding wheel, as well as the better surface finishing
Composite materials are becoming essential and largely used in modern industry, mainly is aeronautics and aerospace industries. This notable demand for these materials, generated from the combination of two or more distinct materials, can be explained by some results obtained: unique and optimized properties specific for each application. One of the main reasons for its large use it is their structural composition, which comes from the fusion of two different materials, resulting into excellent structural properties. Due to the material anisotropy, there is a trend of appering residual stresses and structural distortions, after its processing. For the adequade control of these distortions, it is necessary a machining process called grinding. When grinding these materials, there is a need of a great quantity of cutting fluids (conventional lubrication). In relation to the environmental concerns, new methodologies arise, which intend to reduce this large quantity of cutting fluid, like optimized cooling, the minimum quantity lubrification (MQL) technique and dry grinding. The present work analyzed the aforementioned lubri-cooling methods, on surface grinding of carbon fiber reinforced plastic composities (CFRP's), as alternatives to conventional cooling, in order to mitigate the deleterious effects of cutting fluids. This analysis was conducted through data gathering concerning the process efficiency and the the workpiece surface quality, using the following output variables: bahavior of the tangential force, surface roughness, specific grinding energy, G relation and scanning electron microscopy (SEM). With the results obtained, it can be verified that the MQL technique generated the lowest values of tangential cutting force and griding specific energy. The optimized and conventional methods provided the lowest wear of the grinding wheel, as well as the better surface finishing
Descrição
Palavras-chave
Compósitos polimeros, Refrigeração, Fibras de carbono, Retificação plana, Retificação a seco, Composites, Surface grinding, Optimized cooling, Dry grinding, Carbon fibers
Como citar
VARASQUIM, Francisco Mateus Faria de Almeida. Otimização da retificação tangencial plana de compósitos plásticos reforçados com fibras de carbono. 2011. 89 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências, 2011.