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Efeito das diferentes condições de rotação, avanço, lubrirrefrigerantes em furação convencional e furação por escoamento considerando as propriedades do aço STRENX 700 MCD e a vida útil das ferramentas / Effect of different conditions of rotation, feed, coolant lubrication in conventional drillin...more
O processo de furação convencional é obtido por uma ferramental multicortante, de geometria definida e é um processo empregado em larga escala na indústria. O processo de furação por escoamento é um processo com poucas aplicações quando... more
O processo de furação convencional é obtido por uma ferramental multicortante, de geometria definida e é um processo empregado em larga escala na indústria. O processo de furação por escoamento é um processo com poucas aplicações quando comparado a furação convencional e trabalha com uma ferramenta em alta rotação que é pressionada contra a superfície do material que será perfurado, gerando atrito entre a ferramenta e o material da chapa, resultando numa perfuração considerada especial pelo estado da arte e que gera como resultado uma bucha escoada que é utilizada para um posterior processo de roscagem. Pretende-se avaliar o comportamento do material STRENX 700 MCD um aço de alta resistência e baixo carbono que combina alta resistência e grande ductilidade. Objetivando avaliar o desgaste e a vida útil das ferramentas em furação convencional e furação por escoamento na manufatura do aço STRENX 700 MCD e esta pesquisa serve para contribuir com a fundamentação teórica no intuito de des...
Research Interests: Physics and Humanities
Machining is a process in constant evolution, the search for greater productivity, reliability, and quality of machined materials is fundamental for the constant evolution of the process. The condition of the tool edge is of great... more
Machining is a process in constant evolution, the search for greater productivity, reliability, and quality of machined materials is fundamental for the constant evolution of the process. The condition of the tool edge is of great importance for the tool performance in machining, the edge of a tool after the manufacturing or re-sharpening process has defects such as: microcracks, irregularities, and an extremely sharp edge. The cutting edge treatment is used to remove these defects, which originate from the tool manufacturing and re-sharpening processes. In view of these listed points, this work aims to understand and evaluate the effects of cutting edge treatment by abrasive bristle brushes, taking into account the evolution of wear on the edge and tool life in the end milling process. The abrasive brushes covered in this work are technical brushes from the 3M brand, these brushes have different grain sizes and two different abrasives, silicon carbide (SiC) and aluminum oxide (Al2O...
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Actually, machining without cutting fluid is one of the most discussed topics of the metal-mechanical industry. The high cost of fluids, ecological problems in the work environment and the destination of wastes, as well the health of... more
Actually, machining without cutting fluid is one of the most discussed topics of the metal-mechanical industry. The high cost of fluids, ecological problems in the work environment and the destination of wastes, as well the health of workers, have encouraged the removal or restriction of the use of cutting fluids. The research of the drilling process seeks to adapt cutting conditions and circumstances to perform machining without cutting fluid. Thus, this paper reports a study of the lack’s effects of cutting fluids in high-speed-steel tools HSS M2, in machining of steel AISI P20. For the development of tests were used twist drills DIN 338, with two edges, uncoated. The drills had mainly the mechanisms of abrasion and adhesion. The absence of the cutting fluid became the process quite severe, subjecting the tools to high thermal solicitations. Key words: drilling, dry machining, wear mechanisms.
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This paper presents a study of the tool wear in High Speed Machining (HSM) of hardened steel. The used hardened steel was the AISI H13 with hardness between 52 and 54 HRc. High speed milling experiments were developed to evaluate the wear... more
This paper presents a study of the tool wear in High Speed Machining (HSM) of hardened steel. The used hardened steel was the AISI H13 with hardness between 52 and 54 HRc. High speed milling experiments were developed to evaluate the wear mechanisms for finishing endmill with ball nose and for roughing mill with round insert cutter. The analysis was limited the flank wear. In both processes the tool life was measured and the tests were developed for different cutting conditions for dry machining and different tools. The results show a good tool life for finishing endmill, for this tool the adhesion and the chipping were the limit for a longer lifetime. For roughing mill with round insert cutter the process was restricted to the small depths and moderated cutting speed, and the abrasion mechanism was the main wear on the cutting edge.
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Research Interests: Engineering and Elsevier
This paper presents a study of the forces exerted during drilling of the titanium alloy Ti6Al4V with the application of a Minimal Quantity of Lubricant (MQL). The drilling process was chosen to evaluate the effect of lubrification with... more
This paper presents a study of the forces exerted during drilling of the titanium alloy Ti6Al4V with the application of a Minimal Quantity of Lubricant (MQL). The drilling process was chosen to evaluate the effect of lubrification with MQL, where the lubricant was applied either with an external nozzle (MQL ext) or internally through the tool (MQL int). The feed force Ff and twisting torque Mt were obtained directly. The results show good potential for drilling with MQL applied internally through the tool. The forces obtained show characteristics similar to those obtained with the application of emulsion internally through the tool. However the process is restricted to shallow depths and is limited by the quality requirements of the hole, especially when the lubricant is applied via the external nozzle. A analyze the forces at different parts of the drill was made to evaluate the friction with the walls of the hole and to understand the factors which influence feed force and twistin...
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Electrical Discharge Machining (EDM) is a commonly used process to manufacture of die and molds, due to the capacity of generating deep and complex cavities. The removal of material occurs from a series of discharges between electrode and... more
Electrical Discharge Machining (EDM) is a commonly used process to manufacture of die and molds, due to the capacity of generating deep and complex cavities. The removal of material occurs from a series of discharges between electrode and workpiece. Discharges melt and vaporize material in form of debris, flushed away by the dielectric flow. This work presents AISI H13 steel surface integrity study, machined by EDM process using constant parameters and a copper electrode with different depths of cavity and pulse times. Textures, crack density, roughness and affected layer were investigated. The collected data was submitted to an ANOVA statistical test. The study showed cavity depth as the only significant factor in roughness. Affected layer thickness is not affected by cavity depth and pulse time. Cracks depth and concentration rise with the increase of pulse time and depth of the cavity.
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Electrical discharging machining is a process that uses high-frequency electrical discharges to generate heat, melting and vaporising the workpiece material. Melted material is flushed away by dielectric flushing. However, only part of... more
Electrical discharging machining is a process that uses high-frequency electrical discharges to generate heat, melting and vaporising the workpiece material. Melted material is flushed away by dielectric flushing. However, only part of the molten material is removed, the remaining material resolidifies discharge craters, which affects the integrity of the workpiece. This paper discusses how the flushing flow and the radii of electrode under different machining conditions can affect the roughness and affected layer. Rectangular cavities were machined with a copper electrode in AISI H13 steel. Unilateral side flushing with an immersion flushing was used. An analysis of variance was used to verify the statistical relevance of the results. The obtained data appointed that, under the flushing condition used, independent of the electrode radii, some significant differences were found in roughness and scanning electron microscope (SEM) images. No difference was found in affected layer thickness in different analysed positions of flushing path.
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Purpose: The objective of this paper is to investigate the effect of drill microgeometry and cooling supply in the surface integrity of machined holes. The changes in the holes surface and subsurface due to differences on tools features... more
Purpose: The objective of this paper is to investigate the effect of drill microgeometry and cooling supply in the surface integrity of machined holes. The changes in the holes surface and subsurface due to differences on tools features were presented. Design/methodology/approach: Two types of carbide drills with differences in microgeometry and internal/external cooling were used in the machining of SAE 1045 steel. The surface integrity of the holes was evaluated in terms of surface and subsurface quality. The holes surface was examined using optical microscopy (texture) and roughness measurement. The subsurface analysis included plastic deformations, and micro and nanohardness. Findings: The differences in the cooling supply and drills microgeometry showed influence on surface integrity results. The drill type with internal cooling and improved microgeometry produced holes with a smoother surface and subsurface changes of lower magnitude. The most influent feature of microgeometry...
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The electrical discharge machining (EDM) is a process widely used in machining of complex geometries and hardened materials, conditions that often are not met by conventional machining processes. In EDM the electrode reproduces its image... more
The electrical discharge machining (EDM) is a process widely used in machining of complex geometries and hardened materials, conditions that often are not met by conventional machining processes. In EDM the electrode reproduces its image or geometry on the part and this image is obtained by chip removing process, which is given by high frequency electrical discharges, causing the melting and vaporization of electrically conductive materials. Due to this mechanism of material removal, the surface is subjected to high thermal loads, which heavily influences the surface quality of obtained parts. For the characterization of these surfaces must be considered the surface topography and the metallurgical changes of the subsurface layer, since both characteristics influence the functionality of the machined parts. In addition, several variables related to the EDM process have influence on the characteristics of the generated surface. This work presents a study of the influence of EDM proce...
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... 2008. [2] LUZ, SOC da; SELLITTO, Miguel Afonso; GOMES, Luciana Paulo. ... Vacuum, n. 83, p. 427-434, 2009. [14] WEINERT, K.; INASAKI, I.; SUTHERLAND, JW;WAKABAYASHI, T. Dry Machining and Minimum Quantity Lubrication. ...
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ABSTRACT In this study, we present a methodology for minimizing machining time, where the surface roughness is constrained for the problem. The objective of the methodology is to encounter optimized cutting parameters which reduce... more
ABSTRACT In this study, we present a methodology for minimizing machining time, where the surface roughness is constrained for the problem. The objective of the methodology is to encounter optimized cutting parameters which reduce machining time without reducing the surface quality of the machined workpiece. Three optimization schemes were considered to encounter the minima of a quantity which is a function of machining parameters: (a) sequential quadratic programming, (b) genetic algorithms, and (c) simulated annealing. For the discussion of the methodologies employed, an example of a machined surface is presented. The formalisms are used to obtain the parameters which minimize the machining time while maintaining the surface roughness within acceptable limits.
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Page 1. Instituto Politécnico, Nova Friburgo August 30th-September 3rd, 2004 Paper CRE04 PF34 Estudo do Comportamento da Rugosidade no Fresamento a Altas Velocidades de Corte em Função da Profundidade Axial e do Avanço por Gume ...
Electrical Discharge Machining (EDM) removes material by melting and vaporization as consequence of high temperatures generated by high-frequency electrical discharges. This result changes the material integrity, due to the production of... more
Electrical Discharge Machining (EDM) removes material by melting and vaporization as consequence of high temperatures generated by high-frequency electrical discharges. This result changes the material integrity, due to the production of an affected layer and micro-cracks. In this study, the integrity generated by the use of unilateral side flushing in EDM was evaluated. The experiment consisted of machining square cavities with different parameters. Analysis of texture, roughness, affected layer and micro-hardness were investigated. The results show variations in the thickness of the affected layer at different positions of the machined cavity and showed changes with machining conditions along the flushing path.