Retificação de aço endurecido com aplicação de fluido de corte pela técnica MQL contendo grafeno e nanotubos de carbono

• Ano de defesa: 2022
• Autor(a) principal: Abrão, Bruno Souza
• Tipo de documento: Tese
• Tipo de acesso: Acesso embargado
• Idioma: por
• Instituição de defesa: Universidade Federal de Uberlândia; Brasil; Programa de Pós-graduação em Engenharia Mecânica
• Palavras-chave em Português: Retificação Cilíndrica; Cylindrical Grinding; Aço endurecido; Hardened steel; Fluido de corte; Cutting fluid; Técnica MQL; MQL technique; Nanotubos de carbono; Carbon nanotubes; Grafeno multicamadas; Multilayer graphene; Integridade superficial e sub-superficial; Surface and sub-surface integrity; CNPQ::ENGENHARIAS::ENGENHARIA MECANICA; Engenharia mecânica; Fluidos em metaloplastia; Aço - Tratamento térmico; Aço-carbono
• Link de acesso: https://repositorio.ufu.br/handle/123456789/37319; http://doi.org/10.14393/ufu.te.2022.392

The abrasion machining process has wide application in several industrial sectors for achieving the combination of low roughness values (Ra < 1.6 µm) and narrow dimensional tolerances (IT6 to IT3), however it is a process in which a high specific energy is generated. The abrasive material of conventional grinding wheels has low thermal conductivity and the chips generated are small, so that most of the heat is directed to the workpiece, so becoming essential to use cutting fluid to cool the cutting area. The cooling system most used for grinding is the conventional technique of supplying cutting fluid (flooding). However, due to the growing concern with work safety, environmental and economic issues, it became necessary to study new ways of applying the cutting fluid, with emphasis on the Minimum Quantity of Lubrication (MQL). On the other hand, the MQL technique has limitations regarding the process temperature reduction, which has motivated the development of a new line of research, among them the one that adds solid particles to the fluid to improve the cooling and lubrication functions. In this sense, the present work aimed to study the dispersion of carbon nanotubes and graphene particles in the cutting fluid during the external cylindrical plunge grinding of SAE 52100 hardened steel using different types of abrasive grinding wheel (conventional Al2O3 and seeded gel). The following cutting parameters tested were: the feed speed Vf (1.0 mm/min and 1.5 mm/min) and the workpiece speed Vw (0.29m/s and 0.57 m/s). As a result, there was an increase in the roughness and deterioration of the surface texture with the increase in the feed speed and the reduction in the workpiece speed. The use of the seeded gel grinding wheel and the fluid containing the solid particles resulted in a better finish. The highest Vf and lowest Vw generated the highest microhardness variations and increased cylindricity deviations. The use of the seeded gel grinding wheel and the conditions MQL+Graphene and MQL+Carbon nanotubes minimized the occurrence of thermal damage. The grinding power was reduced with the use of the seeded gel grinding wheel and the fluids containing solid particles.