Influência da utilização do fluido de corte com adição de grafeno na temperatura de usinagem e formação de rebarba no processo de micro fresamento

As time passed, humanity needed the development of new materials used in various activities. High strength materials such as titanium and Inconel for example, had been studied because they are widely used for implants in biomedicine, as well as their use in aerospace and automotive industries. Because of its thermal and mechanical properties, these materials are considered difficult to machine, promoting a rapid wear of cutting tools, primarily caused by the high temperatures in machining. With the development of new materials has emerged the need of developing new manufacturing processes. One of today’s innovative processes is the micro-manufacturing. Being a process with a defined cutting tool geometry, burr formation is a constant and undesirable phenomenon formed during the machininig process. Being detrimental to the manufacturing process, overspending deburring operations are constantly employed leading to increase the aggregate cost to the manufactured material. Assembly components are also impaired if there is no control of the burr, with consequences including the disposal of components due to the occurence of this phenomenon. This paper presents the study of micro-milling Inconel 718, investigating influential parameters in the formation of burrs in order to minimize the occurrence of this phenome non. Different feed rates per tooth and cutting speed are evaluated, and different cutting fluids with different methods of applying the fluid. Adding graphene to cutting fluids was considered as a variable to be investigated, which is considered an excellent solid lubricant, in addition to increasing the thermal conductivity of the cooling solution (AZIMI; MOZAF FARI, 2015). The micro-milling temperature was evaluated in the present work. It was observed a new phenomenon that causes the machined surface temperature decreases below room temperature when using the solution water + oil. This phenomenon is explained in further chapters. In order to unravel this phenomenon, a new test was proposed and, from this test, it can be concluded, comparatively, which cutting fluid has a better cooling property.Using cutting fluid with different thermal properties has shown influence when analy zing burr formation and reducing machining temperature.

Luz e vida: uma proposta de formação continuada de professores

The Course “Light and Life”, which is a product of the present research, is a mediator in helping Science Teachers on how to deal with the Physics classes in secondary school. The aim of the present study was to propose a course which can help Science Teachers with their difficulties in the teaching of Physics in the later years of secondary school, mainly about topics related to the theme Light. The elaboration of the product of this research involved structuring and applying a course of continued formation through the “Fun with Science and Art Museum-DICA, under the theme Light, to Science Teachers of the later years of secondary school, in order to promote an environment of dialogue and problem raising as means of disseminating and discussing the teaching of topics related to Light in the teaching of Sciences. The formation course presented a flexible structure in order to widen the relation between the researcher and the teachers participating in the course, aiming to give an answer to the formative needs of the teachers in relation to the theme proposed. In order to know and discuss the problems and challenges of the teaching of Physics in the Science classes, an approach of insertion and integration of concepts related to the theme Light was conducted, mainly on topics relating to the contents of Physics, Chemistry and Biology, according to the curriculum and the abilities of Sciences worked on in class, through the approach of concepts and practice which approximate the practical and theoretical reality of the formative needs of the teachers involved in this study. This work aimed to understand the relation of Science Teachers with the theme Light and comprehend the relation of the teachers with the present proposal of continued formation promoted by the Museum DICA. The methodological option of this research remained in the domains of qualitative research whose analysis was based on the content analysis. The data collection was carried out through questionnaires and group discussions recorded in audio, besides the participative observation of the researcher. As the research product, the structuring and application of a course of continued formation of Science Teachers of secondary school was proposed, under the thematic Light, and a later restructuring of the course under the same thematic based on the data collected after the application of the referred course, which will be later promoted by the Museum DICA.