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.

A educação a distância e a formação docente

This study was guided by the following question: Is it possible to prepare good teachers for Basic School in Distance Learning (DL) online? The over all objective of this study was to identify and systematize the essential knowledge and skills for the practice of teaching in basic education as well to investigate whe ther the Distance Learning courses which train and prepare future teachers include all the knowledge and skills necessary for teaching practice. This is a qualitative the oretical and bibliographic research that aims to analyze the current stageof the knowledge on this theme. We selected recent papers on this subject, in order to study what has been written by the authors as well to know which are their significant findings. Data were collected from dissertations, thesis and books published on the theme. Preliminarily, the theme of the presentation and contextualization has been made and the argument about the relevance of the study for education. In the second section, we present an overview of the Distance Education in Brazil: coargumentncepts, characteristics, emergence, evolution and regulation. The third section the working environmentin training teachers and students in on line education, targeting to be familiar to Learning Virtual Environments (LVE), analyzing how these new learning spaces are settled and how students and teachers be have in front of the new settings of teaching and learning using Information and Communication Technologies (ICT). In the fourth section aimed to identify which are the essential knowledges and skills that the teacher must master in order to work competently as well to discover which are the personal and professional characteristics of a good teacher in the XXI century. The fifth section studied and analyzed the current situation with in Distance Education is carried out in Brazil. We identified the most significant contributions of Distance Learning to Brazilian Education System in order to contribute to advances in the debate on the effectiveness of teacher training courses in distance education mode online.Finally in the sixth section were made final remarks and presented the study results.