Portaferramentas para torneamento com refrigeração interna baseada na mudança de fase do fluido

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da composição química e da microestrutura na usinabilidade do aço de corte fácil com adição de chumbo (SAE12L14)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Proposição de um novo método de medição do desgaste em ferramentas de corte empregadas em operações de fresamento da madeira

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Resistência mecânica de juntas coladas em madeira de Eucalyptus sp

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avanços no torneamento utilizando um porta-ferramentas refrigerado internamente com fluido em mudança de fase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Uma contribuição ao estudo das tensões residuais no fresamento

Pós-graduação em Engenharia Mecânica - FEIS

Hot turning of a difficult-to-machine steel (sae xev-f) aided by infrared radiation

A possible way for increasing the cutting tool life can be achieved by heating the workpiece in order to diminish the shear stress of material and thus decrease the machining forces. In this study, quartz electrical resistances were set around the workpiece for heating it during the turning. In the tests, heat-resistant austenitic alloy steel was used, hardenable by precipitation, mainly used in combustion engine exhaustion valves, among other special applications for industry. The results showed that in the hot machining the cutting tool life can be increased by 340% for the highest cutting speed tested and had a reduction of 205% on workpiece surface roughness, accompanied by a force decrease in relation to conventional turning. In addition, the chips formed in hot turning exhibited a stronger tendency to continuous chip formation indicating less energy spent in material removal process. Microhardness tests performed in the workpieces subsurface layers at 5 m depth revealed slightly higher values in the hot machining than in conventional, showing a tendency toward the formation of compressive residual stress into plastically deformed layer. The hot turning also showed better performance than machining using cutting fluid. Since it is possible to avoid the use of cutting fluid, this machining method can be considered better for the environment and for the human health.

Estudo do fresamento de madeiras em centro de usinagem CNC

The lack of research related to wood machining processes, including the milling, as well as the increased use of this material in the industrial sector, it creates a need to increase research involving these processes, as the sector is in full technological and environmental remodeling. This paper studies the process of milling wood, presenting an analysis of the effects of cutting speed on surface quality by measuring roughness. We used a forward speed three cutting speeds, two species of wood (Pinus elliottii and Eucalyptus grandis) and two milling tools (roughing and finishing) machined by milling concordant and discordant. Each condition was repeated six times, and the measurements were performed in the opposite direction and in favor of cutting tool, generating results of the parameters Ra (average roughness) totaling 144 trials with it. These results were statistically analyzed using analysis of variance and Tukey test. Finally it was concluded that there are significant differences between the results of varying roughness when cutting speeds, milling and types of machining types tested

Experimental and numerical study of heat transfer in hot machined workpiece using infrared radiation

One of the greatest problems found in machining is related to the cutting tool wear. A way for increasing the tool life points out to the development of materials more resistant to wear, such as PCBN inserts. However, the unit cost of these tools is considerable high, around 10 to 20 times compared to coated carbide insert, besides its better performance occurs in high speeds requiring modern machine tools. Another way, less studied is the workpiece heating in order to diminish the shear stress material and thus reduce the machining forces allowing an increase of tool life. For understanding the heat transfer influences by conduction in this machining process, a mathematical model was developed to allow a simplified numerical simulation, using the finite element method, in order to determine the temperature profiles inside the workpiece.

Studio e sperimentazione di leghe ad elevata deformazione per applicazioni nel settore della prima lavorazione di materiali lapidei

Studio del componente di supporto del cavo utensile per taglio di materiali lapidei. Analisi delle applicazioni di leghe superelastiche e delle modalità di realizzazione del cavo utensile complessivo in relazione a specifiche esigenze poste a livello industriale.

Estudio experimental del desgaste del flanco y de la rugosidad superficial en el torneado en seco de alta velocidad del acero AISI 316L

La mejora continua de los procesos de fabricación es fundamental para alcanzar niveles óptimos de productividad, calidad y coste en la producción de componentes y productos. Para ello es necesario disponer de modelos que relacionen de forma precisa las variables que intervienen en el proceso de corte. Esta investigación tiene como objetivo determinar la influencia de la velocidad de corte y el avance en el desgaste del flanco de los insertos de carburos recubiertos GC1115 y GC2015 y en la rugosidad superficial de la pieza mecanizada de la pieza en el torneado de alta velocidad en seco del acero AISI 316L. Se utilizaron entre otros los métodos de observación científica, experimental, medición, inteligencia artificial y estadísticos. El inserto GC1115 consigue el mejor resultado de acuerdo al gráfico de medias y de las ecuaciones de regresión múltiple de desgaste del flanco para v= 350 m/min, mientras que para las restantes velocidades el inserto GC2015 consigue el mejor desempeño. El mejor comportamiento en cuanto a la rugosidad superficial de la pieza mecanizada se obtuvo con el inserto GC1115 en las velocidades de 350 m/min y 400 m/min, en la velocidad de 450 m/min el mejor resultado correspondió al inserto GC2015. Se analizaron dos criterios nuevos, el coeficiente de vida útil de la herramienta de corte en relación al volumen de metal cortado y el coeficiente de rugosidad superficial de la pieza mecanizada en relación al volumen de metal cortado. Fueron determinados los modelos de regresión múltiple que permitieron calcular el tiempo de mecanizado de los insertos sin que alcanzaran el límite del criterio de desgaste del flanco. Los modelos desarrollados fueron evaluados por sus capacidades de predicción con los valores medidos experimentalmente. ABSTRACT The continuous improvement of manufacturing processes is critical to achieving optimal levels of productivity, quality and cost in the production of components and products. This is necessary to have models that accurately relate the variables involved in the cutting process. This research aims to determine the influence of the cutting speed and feed on the flank wear of carbide inserts coated by GC1115 and GC2015 and the surface roughness of the workpiece for turning dry high speed steel AISI 316L. Among various scientific methods this study were used of observation, experiment, measurement, statistical and artificial intelligence. The GC1115 insert gets the best result according to the graph of means and multiple regression equations of flank wear for v = 350 m / min, while for the other speeds the GC2015 insert gets the best performance. Two approaches are discussed, the life ratio of the cutting tool relative to the cut volume and surface roughness coefficient in relation to the cut volume. Multiple regression models were determined to calculate the machining time of the inserts without reaching the limit of the criterion flank wear. The developed models were evaluated for their predictive capabilities with the experimentally measured values.

Machinability Study of an aluminum-copper alloy

Machinability of materials is one of the factors that make us wonder what tools to use and what material is best suited for a particular cutting tool and which process is more efficient in the production of a component. In the case of parts for the aerospace industry, manufacturing processes assume greater importance due to the extreme demands on reliability and quality.

Effect of drill speed on bone damage during drilling

The boné drilling is a common surgical procedure in clinicai intei-ventions including the dentistry. Although not a novelty in medicine, the penetration of a sharp tool in the boné tissue continues to be a clinicai and surgical challenge, as many pertinent questions still remain without solutions. Mechanical damage to the boné tissue is one of the common complication associafed with the drilling process [l]. An excessive force generated by a cutting tool can lead to the formation of microcracks and fractures, and even cause permanent damage in the boné tissue that, in tum, can delay postoperative recovery [2]. The main goal of this paper is to investigate the effect of drill speed on mechanical damage during drilling of solid rigid foam materiais, with similar mechanical properties to the human boné. Experimental tests were performed on biomechanical blocks instrumented with strain gauges in different surface positions during the drilling process. Finite element (FE) simulations were performed to simulate the drilling process and validated with experimental results.

The Problem Sensitization Robotic Complex Drilling and Milling of Sandwich Shells of Polymer Composites

In clause is given robotic a complex for drilling and milling sandwich shells from polymeric composites. The machining of polymeric composite materials has technological problems. At drilling sandwich shells there is a probability of destruction of a drill from hit of the tool in a partition. The system sensibilization robotic complex for increase of reliability of work of the cutting tool of the small size is offered.

Food and nutrition security and the eradication of hunger CELAC 2025: Furthering discussion and regional cooperation

The region of Latin America and the Caribbean can boast a successful track record in the process of eradicating hunger: it is the only region in the world that has halved both the proportion of people who suffer from hunger (the target set in the Millennium Development Goals) and their absolute number (the target set at the World Food Summit of 1996). This publication aims to provide the region’s countries with up-todate and timely information on the status of food and nutrition security; on the role in eradicating hunger played by the different areas such as agriculture, agrifood trade and natural resources management; and on the possibility of successfully addressing the twin burden of malnutrition, in a context where the effects of climate change could threaten the progress achieved in Latin America and the Caribbean thus far. The CELAC Plan for Food and Nutrition Security and the Eradication of Hunger 2025 is a cross-cutting tool for achieving the Sustainable Development Goals of the 2030 Agenda for Sustainable Development; and it thus encourages the countries of Latin America and the Caribbean to redouble their efforts to identify key policy areas that will make it possible to speed up and consolidate the process of eradicating hunger and tackle the twin burden of malnutrition in the region, in which overweight and obesity are increasingly adding to that scourge.