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published_or_final_version / abstract / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

published_or_final_version / abstract / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

Orientador: Eduardo Carlos Bianchi / Banca: Luiz Eduardo de Angelo Sanchez / Banca: Thiago Valle França / Banca: Rosemar Batista da Silva / Banca: Jaime Gilberto Duduch / Resumo: O presente estudo aborda novas técnicas produtivas para o setor da usinagem por abrasão, destacando as tecnologias limpas e menos agressivas ao meio ambiente, tais como o emprego do fluido de corte biodegradável sem adição de água com o objetivo de reduzir a quantidade do fluido, com o emprego da técnica da mínima quantidade de lubrificação - MQL. Neste trabalho foram feitos estudos sobre a influência da lubri-refrigeração e a técnica MQL no processo de retificação, almejando a integridade da superfície sem danos microestruturais. Dessa forma, a técnica MQL pode ser comparada com ao método convencional de aplicação de fluido no processo de retificação, visando um padrão de qualidade similar. O material empregado foi o aço ABNT 4340 em forma de disco, caracterizados através dos ensaios de rugosidade, do desvio de circularidade, do desgaste diametral do rebolo, da análise metalográfica, da microscopia óptica, da microdureza e da análise da influência da lubri-refrigeração nas variáveis dos sinais de potência e emissão acústica. A execução e o controle das etapas processadas durante as vazões da lubri-refrigeração através do método convencional e da técnica MQL com e sem limpeza da superfície de corte do rebolo, foram fundamentais para obter peças compatíveis com a estrutura esperada, proporcionando assim uma evolução para as etapas subsequentes do processo de retificação. Os parâmetros de vazão pela técnica MQL que mais se destacaram foram na faixa de 30 a 60 ml/h, tendo como d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present study address new production techniques for the abrasion machining sector, hihglighting the clean and less aggressive technologies to the environment, such as the use of biodegradable cutting fluid without addition of water in order to reduce the amount of fluid with the Minimal Quantity Lubrification (MQL). In this work, studies were done on the influence of the flood coolant and the MQL technique in the grinding process, aiming the integrity of the surface without microstructural damages. Thus, the MQL technique can be compared to the conventional fluid application method in the grinding process, aiming at a similar quality standard. The material used was disc-shaped ABNT 4340 steel, characterized by roughness tests, circularity deviation, diametrical grinding wheel wear, metallographic analysis, optical microscopy, microhardness and analysis of the influence of the flood coolant. In the variables of the power and acoustic emission signals. The execution and control of the steps processed during the flood coolant flow through the conventional method and the MQL technique with and without cleaning of the grinding wheel were fundamental to obtain parts compatible with the expected structure, thus providing an evolution to the subsequent steps of the grinding process. The flow parameters of the MQL technique that stood out most were in the range of 30 to 60 ml/h, having as a differential the inclusion of the cleaning of the cutting surface of the grinding wheel, where it improved substantially in relation to the method without cleaning, which presented the of the wheel clogging, thus making this method unfeasible. The results of the studies how that MQL applications with clean cutting surface of the grinding wheel provided a better performance in relation to the MQL method without cleaning, this way, the cleaning method was the condition that most qpproached the... (Complete abstract electronic access below) / Doutor

This research effort highlights emerging areas in the field of robotic polishing and includes an extensive literature survey conducted by the author. This survey shows that areas in need of further investigation for achieving automated polishing are surface measurement, CAD/CAM integration and polishing mechanics. The work conducted has been based on the use of an available robot end-effector for polishing unknown three-dimensional surfaces. A model for determining the mass of material removed during the polishing process is based on hardness testing, surface grinding and milling theory. Using this model the material removed during the polishing process is compared to results from practical experiments. Polishing trajectory for a robot-end effector to follow has been produced using CAD files in Initial Graphics Exchange Specification (IGES) format. Using these files and two types of polishing patterns, the surface roughness of polished surfaces has been compared for simple planar polygonal surfaces. / Master of Engineering (Hons)

Thesis (M. Phil.)--University of Hong Kong, 2007. / Also available online.

Thesis (M. Phil.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1940. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed March 9, 2010) Includes bibliographical references (p. 60-62) and index (p. 63-64).