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Wear is the main mechanism that reduces the lifetime of forging dies used in closed die forging. A newly proposed approach to decrease die wear is the concept of protective sheet metal forging die covers, where an inexpensive and easy-to-exchange sheet metal die cover is used to protect forging dies. After this concept has been fundamentally validated by previous studies, the presented work aims to further evaluate the protective effects of this concept regarding wear reduction. First, an application-oriented experiment of the die cover concept on forging dies for producing square flange was conducted. On both the forging dies with and without die covers 100 forging strokes were carried out. The wear depths of both forging dies were then measured and compared. The results indicated that the forging die with die covers has up to 98% less wear than the forging die without die covers. The expected tool life of the forging die with die covers is therefore 600% longer. In addition, the die cover applied in the experiment achieved the service life of 100 forging cycles without being distorted, which reached the maximum service life of the die cover concept so far.

Morphological evolution of microstructures and tensile properties in Mg-Al alloy containing La and Ca (Mg-6Al-3La-1Ca) processed by rheocasting with different solid fractions (fs) were investigated at this paper. An apparatus for semisolid metal alloy processing was used to melt and to obtain the rheocast material. Isothermal mechanical stirring experiments were carried out with fs = 0.30, 0.49 and 0.61 at 950 rpm for 10 min. A conventional casting (no stirring) was also obtained for comparisons. Results showed that microstructure in conventional casting is composed by α-Mg dendritic matrix and Al11La3, (Al,Mg)2Ca and Mg2Ca compounds. Non-dendritic and globular microstructures were observed in the rheocasting. For fs = 0.30 the acicular Al11La3 phase precipitated at globule boundaries, while for the fs = 0.49 and fs = 0.61 the acicular phase precipitated both inside and at globule boundaries. The ideal rheocasting condition was achieved fs = 0.30 due to the improvement of 76% for the ultimate tensile strength (UTS) and 80% in the strain to fracture when compared to the conventional casting. Fracture surface analysis pointed to a mixed ductile-brittle fracture mode containing dimples and quasi-cleavage facets for the lowest solid fraction (fs = 0.3), and a fully brittle fracture mode consisting exclusively of cleavage planes for the highest solid fraction (fs = 0.61).

This paper aims to evaluate the morphological evolution of a magnesium-aluminum alloy (Mg-6Al-3La-1Ca) processed by a mechanical stirring process (MSP) with different stirring times. An apparatus for semisolid metal alloy processing was used to melt and obtain rheocast material. Transformation temperatures were determined at a slow cooling rate using computer-aided cooling curve thermal analysis (CA-CCTA) and differential scanning calorimetry (DSC). Isothermal mechanical stirring (605 °C), at 950 rpm, was carried out with a solid fraction of 0.29 and stirring times of 0, 1, 2, 4, 8 and 10 min, followed by fast cooling in water. The results showed that the microstructure after conventional casting (0 min—no stirring) is composed of an α-Mg dendritic matrix, Al11La3, (Al,Mg)2Ca and Mg2Ca compounds. With the 1-min stirring time, it was not possible to obtain globular structures. For stirring times longer than 2 min, a primary α-Mg globular morphology was obtained. Microstructures with 2 min of stirring time showed better globularization than those obtained under the other conditions. Morphological changes were observed for Al11La3 and (Al,Mg)2Ca after the MSP followed by fast cooling.

Metal Injection Molding is a well-known powder metallurgy technology, which allows net-shaped parts to be produced with a high degree of automation and reduced costs in large-scale production. However, shape retention during sintering of porous parts remains a challenge. The present study demonstrates that plasma assisted debinding and sintering of injection-molded parts is a promising route for manufacturing highly porous Fe-P-based parts, improving porosity amount and dimensional accuracy, avoiding surface distortion of injection-molded parts while decreasing processing time. In this study, the effect of plasma sintering was analyzed regarding dimensional accuracy, porosity, phase composition and microstructure of highly porous Fe-2wt%P parts.

Cold extrusion is known as a metal forming process and used due to its dimensional precision. However, the process definition is obtained by empirical methods where experiments are performed previously and based on a “trial and error” method. To reduce costs, companies have been looking for the support of numerical simulation softwares with metal forming application. This study describes the investigation of the effect of different levels for prestressing of cold extrusion gear tool by using the software Simufact Forming. The dimensional deviations of the gear tooth were obtained from two numerical simulations and compared. The application of shrink rings for the prestressing of tooling was evaluated using two different methods to compare their efficiency. The first one is using conventional shrink rings with tool steel, while the second is the stripwinding concept developed by the company STRECON. To produce spur gears, the low carbon steel SAE 10B22 was used.

Incremental Sheet Forming (ISF) and particularly its Single Point (SPIF) variant has been studied intensively over the last years given the potential for low-cost prototyping and small batches production. Numerical and experimental works have been covering a widespan of materials and geometries. This paper fills an important gap regarding studies of the SPIF process applied to brass alloys, and particularly the commonly used Cu-35Zn brass alloy. Despite being a material widely used in industry for centuries, with excellent cold formability and innumerous applications, there is still no relevant information on the mechanical response and properties of this material under SPIF. This research is based in SPIF experiments with brass alloy sheets with different thicknesses (0.50, 0.70 and 1.00 mm), to obtain data such as forming forces or forming fracture lines to be compared against standard forming limit diagrams or against other materials under ISF. Other data like friction during the process was evaluated as well. Fifteen sets of experiments were conducted, using different values of step down (0.10, 0.50 and 1.00 mm) and two forming tools with diameters 10 and 15 mm.

This paper presents a system for characterization of thermoelectric generators (TEGs) for energy harvesting. This system can monitor and characterize up to three TEGs simultaneously and it is comprised by two main electronic circuits: The first one is composed by twelve input channels being three for reading voltage, three for reading current by making use of instrumentation amplifiers (reference ACS712) and six thermocouples for signal reading (

The aim of this work is to analyse options of different powder metallurgy tools design with upper punch adapted with springs and its benefits with regards green density of the parts compacted in hydraulic press. Crack of the parts also were observed.

The article presents the results of research that aims at training and consolidation of knowledge and their use for thermoelectric energy harvesting. Therefore, we present a numerical modeling for design and dimensioning of micro electric power generating sources, from theoretical performance curves of thermoelectric modules and temperature gradients for future applications in industrial processes. The final result appears very attractive, since the developed experimental analysis shows promising results, given that many processes generate energy harvesting and, in addition, the cogeneration of power using thermoelectric modules is totally clean, which prevents the emission of gaseous pollute to the environment.

Metal injection molding (MIM) is a near-net-shape manufacturing process suitable for the production of small-size and complex-shape components. As a cost-effective and flexible manufacturing method, it may have distinct advantages over other methods when it comes to the manufacturing of implantable medical devices. However, up till now, the potential for MIM to be employed in the commercial-scale manufacturing of implantable medical devices has been insufficiently exploited. In the present research, an attempt was made to produce porous pure iron, as a metallic degradable biomaterial potentially for stent application, via the MIM route. The effects of iron powder loading and sintering temperature on the porosity, microstructure, mechanical properties, surface properties and in vitro degradation behavior of MIM iron were investigated. The results obtained were compared to those of cast iron. It was found that the amount of porosity retained in the as-sintered specimens had a major effect on their surface and mechanical properties. MIM iron exhibited strengths between those of magnesium alloys and 316 L stainless steel and very high ductility — a specially required property of stent materials. Its degradation rates in Hank's solution were superior to the degradation rate of cast iron. Interestingly, the material made from the feedstock containing 66% of iron powder, above the critical powder loading, showed the highest elongation and a good in vitro degradation rate. In conclusion, MIM is a promising method to be developed as a new route to produce thin-wall tubes for biodegradable stents.

The contact pressure acting on the sheet/tools interface has been studied because of growing the concern about the wear of tools. Recent studies make use of numerical simulation software to evaluate and correlate this pressure with the friction and wear generated. Since there are many studies that determine the coefficient of friction in sheet metal forming by bending under tension (BUT) test, the contact pressure between the pin and the sheet was measured using a film that has the ability to record the applied pressure. The vertical force applied to pin was also measured. The results indicate that the vertical force is more accurate to set the contact pressure that using equations predetermined. It was also observed that the contact area between the sheet and the pin is always smaller than the area calculated geometrically. The friction coefficient was determined for the BUT test through several equations proposed by various authors in order to check if there is much variation between the results. It was observed that the friction coefficient showed little variation for each equation, and each one can be used. The material used was the commercially pure aluminum, alloy Al1100.

In this study the soft magnetic alloy Fe-3Si-0.75P (wt%) was obtained by mechanical alloying through powder metallurgy. The processing included the formulation of metallic powder, wet milling for 1 h, 3 h, 6h and 9 h, in an attritor mill using alcohol P.A. as a lubricant. Cold compaction was then performed in a floating die under 600 MPa pressure and, finally the ring-shaped test specimens were sintered at 1150 °C for 1h. The electrical, physical and magnetic properties were then analyzed using the following assays: Laser granulometry, density, metallography, hysteresis curve and AC permeability, resistivity and XRD. The results showed a strong influence of milling time on magnetic properties of the alloy. There was a decrease in grain size with the milling time, which is likely the cause of increased in magnetic properties.

An analysis of results, obtained in the development of thermoelectric materials for electricity generation during the last 130 years, shows that they are comparable to those obtained as early as the nineteenth century. One of the main factors responsible for the stagnation in this area is the use of inappropriate criteria for the evaluation of material quality. The most popular criterion used for this purpose is the Thermoelectric Figure of Merit. The criterion of usefulness proposed in this paper is free of imperfections of the Thermoelectric Figure of Merit and may be considered as alternative to it. The criterion of usefulness shows, among other things, that it is reasonable to develop thermoelectric pairs both with high and relatively low thermoelectric efficiency. Its application would make it possible to avoid the creation of useless materials. This is especially important under conditions of limited research funding.

This work has the objective of evaluating the effect of electromagnetic stirring (EMS) used in continuous ingot (CI) in the mechanical and metallurgical properties of hot forged flanges of AISI 1025 steel. Three conditions of raw material were supplied and compared before the forging process: one from CI using EMS; the other, prevenient from CI without EMS, and the last, with CI without EMS, and, subsequently, submitted to hot rolling process. Billets were extracted from these raw materials to manufacture connection flanges through hot forging. To evaluate the mechanical properties of the forged pieces, tension, hardness and impact tests were done, and the microstructure was observed by optical microscopy. Macrographs and penetrating liquid non-destructive testing were also done. The results of the above-mentioned tests showed proximate mechanical and metallurgical properties approved by the reference norm (ASTM A105) of the flanges manufactured with the raw materials obtained by CI with EMS and hot rolling.

In recent decades,the forming area advanced both in terms of material used as well as in flexibilityand process cost reduction. New processes are been studied, including theIncremental Sheet Forming – ISF. The ISF is a process characterized by theproduction of small batches of parts, rapid prototyping, and manufacturingflexibility with reduced operational cost. This study aims to compare thecomputer simulation with real experiments from ISF. The results of strain pathsof the three main strains simulated were consistent with the experimentalmanufacture of a symmetrical sample.

This work addresses through bibliographies and experiments the behavior of sheet brass 70/30 for Incremental Sheet Forming process - ISF, based on the parameters: wall angle (), step vertical (ΔZ) strategy and the way the tool. Experiments based on the method called Single Point Incremental Forming - SPIF. For execution of practical tests, we used the resources: software CAD / CAM, CNC machining center with three axles, matrix incremental, incremental forming tool and a device press sheets. Furthermore, measurement was made of the true deformation () and thickness (s1). Practical tests have shown that the spiral machining strategy yielded a greater wall angle, compared to the conventional strategy outline.

The present work is focused on ferrous powder metallurgy and presents some results of a development of a suitable masteralloy for use as an additive to iron powder for the production of sintered steels. The masteralloy was produced by melting a powder mixture containing approximately Fe + 20% Ni + 20% Mn + 20% Si + 1% C (wt%), in order to obtain a cast billet that was converted into fine powder by crushing and milling. It was observed presence of SiC in the masteralloy after melting that is undesirable in the alloy. Si element should be introduced by using ferrosilicon. Sintered alloys with distinct contents of alloying elements were prepared by mixing the masteralloy powder to plain iron powder. Samples were produced by die compaction of the powder mixtures and sintering at 1200 °C in a differential dilatometer in order to record their linear dimensional behaviour during heating up and isothermal sintering, aiming at studying the sinterability of the compacts. Microstructure development during sintering was studied by SEM, XRD and microprobe analyses.

The magnetic cores of rotating electrical machines, such as electric motors and generators, are generally made using laminated steel sheets. However, in certain types of special electrical machines, such as servomotors that operate at high frequencies, it is possible to construct these cores into single solid blocks using the Powder Metallurgy (P/M) process. The advantages of using P/M include lighter machines that consume less energy and perform better. Thus, this work aimed to conduct a comparative study on the electrical and magnetic properties of some soft magnetic composites made from iron powder combined with different phenolic resins: HRJ-10236, SBP-128, SP6600 and SP6601, with mass percentages varying from 0.5% to 3.0%. The influence of different resin contents on the magnetic properties of the composites was analyzed, including relative permeability, saturation induction and the losses, as well as the electrical resistivity. The best results recorded were: saturation induction of 0.64 T for the composite Fe–RA0.5, electrical resistivity of 5020 μΩ m for Fe–RC0.5, magnetic hysteresis losses of 0.45 W/kg for Fe–RB0.5 and total magnetic losses of 0.30 W at 1 kHz, 20% lower than in laminated steel cores.

This paper presents the development of a methodology to manage the mechanic vibration and temperature from Small Wind Turbine (SWT). The objective with this research is propose a new diagnostic and protection tool through analysis and monitoring signals of vibration and temperature from wind turbines, aiming predict a need of preventive maintenance and mostly avoids catastrophic failures. For this feature the system will be composed of a Triple Axis accelerometer who will identify vibration, thermocouples to identify the temperatures at critical points of wind turbine, a microcontroller hardware which will make acquisition and processing of signals from sensors and finally a wireless transmission system using technology ZigBee. The post processing is performed remotely through a computer that receives the data submitted via wireless network presenting them to the user via graphical interface. The software of User friendly interface will have the functionality plus online display of received data also the possibility of storing and reporting data rates of vibration and temperature obtained during monitoring. Finally featuring the prototype of the hardware and software as well as some results obtained in experimental scale.

This work has the purpose of studying loudspeakers in which the cores usually constructed from cast iron or rolled metal are replaced with parts of alloy obtained from the Powder Metallurgy process. The study comprises the obtaining of hysteresis curves of pure iron and some sintered alloys such as FeP, FeNi and FeSi and simulation by the finite element considering a conventional topology of a commercial loudspeaker. The simulations include the evaluation of flow in the air gap and a theoretical study of the powers developed compared to loudspeakers with conventional cores. Keywords: powder metallurgy, simulation by the finite element, loudspeakers.

This article discusses the preliminary studies of the Single Point Incremental Forming (SPIF) process applied brass alloy Cu-35Zn, with different sheet thicknesses and formed geometries. Despite being a material widely used in industry, with excellent cold formability, there is still no relevant research on this material concerning SPIF. As a result of these preliminary studies, the necessary forces (F) during the process, the true strain (e1, e2) and maximum wall angle (ψ) supported by materials are presented and discussed.

The parameters for conventional powder-metallurgical production of a CoCrMo alloy for dental implants were determined. With the application of these parameters an alloy with sufficient green density, low porosity after sintering, considerable hardness and spontaneously passive behavior in the Ringer solution can be achieved. The comparison of samples with different sintering temperatures revealed that a slight variation of the sintering temperature can have a considerable effect on the physical, mechanical and electrochemical properties of the alloy.

No presente trabalho, foi feito um estudo sobre caracterização parcial de uma liga Nitinol atuador tipo M fabricada pela Memory-Metalle. Através dos resultados obtidos em Calorimetria Diferencial de Varredura mostraram-se as temperaturas de transformação de fases onde ocorrem as propriedades notáveis, efeito memória de forma e superelasticidade. Estas temperaturas irão determinar a aplicação da liga no produto. As temperaturas transformação de fases são definidas como As (austenite start), Af (austenite finished), Ms (martensite start) e Mf (martensite finished), ou seja, início e fim da transformação austenítica e início e fim da transformação martensítica. In this work, it was studied a partial characterization of a Nitinol actuator M-type alloy, manufactured by Memory- Metalle. From the results obtained in differential scanning calorimetry, it was shown the temperatures of phase transformation where occur the remarkable properties, shape memory effect and super-elasticity. These temperatures will determine the alloy application in the product. The phase transformation temperatures are defined as As (austenite start), Af (austenite finished), Ms (martensite start) and Mf (martensite finished), which means beginning and end of austenite transformation and the beginning and end of the martensitic transformation.

The aim of this work was the development of magnets in a ring form, four poles, for speed sensor of motorcycles, from barium and strontium ferrites. The model of the magnets developed was based on magnets already manufactured for this purpose. Thus, several raw materials were tested with additive variation. The samples were prepared and measured, and the data were compared to commercially produced magnets. Finally, the magnets were mounted in the speed sensors and field tests were carried out. The magnets developed showed excellent results as having the highest remanent magnetism of 500 Gauss for the PFL barium ferrite alloy with 4% of stearic acid and 1 or 2% of silica, resulting 20% above the required magnetism. Keywords: ferrite magnets, powder metallurgy, speed sensor.

Este trabajo tiene el objetivo de dimensionar un biorreactor de forma optimizada. El dimensionamiento correcto y la elección de materiales son ítems imprescindibles para garantizar un buen funcionamiento y rendimiento de la planta para la generación de biogás. Las herramientas computacionales pueden ayudar en el proyecto y dimensionamiento de plantas de biogás. En este trabajo se han ejecutado simulaciones computacionales para conocer el espesor mínimo de las paredes del biorreactor, considerando tres aceros: AISI 318, AISI 316 L y ASTM A36. La simulación de los biorreactores para dimensionamiento y la elección de los materiales se han desarrollado con el uso de software de CAE FEMAP NASTRAN 10.0.2. Los resultados muestran que el material óptimo es el acero AISI 318 mientras que los aceros AISI 316 L y ASTM A36 tuvieron un comportamiento semejante en la simulación. The objective of this work is to optimize and scale a bioreactor. The design and choice of materials are essential aspects to ensure proper operation and performance of the plant for biogas generation. Computational tools can assist in the design and sizing of biogas plants. Computer simulations were performed to determine the minimum plate thickness of the bioreactor considering three types of steels: AISI 318, AISI 316 L y ASTM A36. The simulation of bioreactors for the design and for the choice of materials is done using the software CAE FEMAP NASTRAN 10.0.2. The results show that the optimum material is steel AISI 318 while the steels AISI 316 L y ASTM A36 presented a similar behavior during simulation.

Forging is one of the main processes used to manufacture metal components for a broad range of applications. This occurs mainly because forged products are highly reliable and present superior mechanical properties. However, lately the competitiveness of forged products has been threatened, since the difference between their superior performance and the performance resulting from other processes has lessened continuously. This has obliged the forging industry to invest in optimizing its processes, saving in raw materials and energy. In this context, the use of numerical simulation of the forging process has become an increasingly reliable tool in seeking this optimization. This study uses the commercial software QForm 3D, version 3.2.1.1, to analyse two forging processes, one by hot forging and one by cold. In the case of hot forging, work on a component with axial symmetry is looked at from which a gear is machined. Currently the part is forged in three stages based on an initial billet with a 7.0 kg mass. Forging is performed in a 40 NM mechanical press with an initial temperature of 1200°C. The hot forging process is optimized and this results in a saving of about 5% in material. In the cold forging case it is shown that the process, as designed, results in laps in the final part, and in possible tool failure due to excess load. In both cases, the material used is DIN 1.7131 (16MnCr5) steel.

Este trabajo tiene el objetivo de estudiar y analizar las propiedades mecánicas de la aleación que presenta en su composición Fe-Cu-C-Ceniza ligera obtenida por pulvimetalurgia convencional. Se determinó la densidad aparente, la curva de compresibilidad y se compactaron las muestras de los compuestos con diferentes porcentuales de ceniza. Se realizó la sinterización de las tres aleaciones generadas en atmósfera controlada por argón a temperatura de 1150°C. También se realizó ensayo de densidad, dureza y análisis micrográfico de las muestras. Analizando las propiedades presentadas, los resultados muestran que se puede utilizar la ceniza ligera en balance con la aleación Fe-Cu-C en concentración de 4,8%.

Resumen Se presenta una investigacion relacionada con un sistema de compresion para biogas a escala piloto, buscando facilitar la utilizacion y comercializacion de este biocombustible. El estudio considera el tratamiento, filtracion y compresion del biogas como tambien su almacenamiento, transporte y la comercializacion. El sistema propuesto esta compuesto por la seccion de filtracion, reduccion de gases no combustibles (como dioxido de carbono) y la seccion de compresion para ser envasado en cilindros. El proceso utiliza el propio biogas como combustible en los motores y equipos. Se establecieron diferentes niveles de presiones para su utilizacion en diversas aplicaciones obteniendo datos sobre compresion, flujo y composicion del biogas. Palabras clave: biogas, biometano, compresion de biogas, filtraje de biogas, biocombustibles Biogas and Biomethane Compression System Abstract This work presents research involving a pilot scale biogas compression system. In an attempt to make it easier to use and commercialize this biofuel, the study looks at its treatment, filtration and compression. The process studied enables storage, transport and sale of biogas. Without a compression system, the use of biogas is restricted to the production site. On the other hand, when biogas is filtered and compressed there are several different applications in homes, industry, automotive vehicles, and other cases. The system is composed of a sector for filtration, reduction of noncombustible gases such as carbon dioxide and a compression sector for filling cylinders. The process uses biogas itself as fuel for motors and equipment. Different levels of pressure were established to use in various applications. In the experiment, data on compression, flow and composition of the biogas were obtained.

There are many remote experiments currently being created, but just few of these remote experiments are from the field of metallurgical engineering. The purpose of this article is to describe the development of the remote compression test machine. This experiment is an educational experiment aimed to conduct a compression test via the internet. It uses the microcomputer Raspberry Pi as the main data control. This remote experiment is available in a website, where the students can control and monitor it and export the output data. The tests realized in the remote compression test machine demonstrated that the output is similar to industrial machine allowing its use as a didactic experiment.

This paper shows friction results obtained through compression ring tests for two commercially-available lubricants (i.e., Oildag and Deltaforge) applied in the hot forging of aluminum alloys. The experiments were performed with AA 6061 F aluminum alloy samples with the goal of observing the behavior of each lubricant in several conditions of temperature (200, 300, and 450 °C), strain rates (1, 10 and 50 s-1), and strain (25, 50 and 75%). The friction coefficients for each lubrication condition were established by means of calibration curves determined from finite element calculations with the use of the PEP/Larstran software package. An Analysis-of-Variance approach for the ring's internal diameter was followed in order to evaluate the performance of the lubricants. The results indicated that the Oildag lubricant presents a better stability as well as lower friction coefficients than the Deltaforge lubricant for the range of conditions tested, which translates into a better friction condition at die-part interface.

This paper describes o development an remote experiment which used an didactic press to study of Hooke's Law in way theoretical-practical. The tests demonstrated that the laboratory has the potential educational, returned as a list of values consistent with Hooke's Law. 40 tests were performed to validate the experiment

This work aims at showing the feasibility of partial substitution of the machining process by hot forging, to obtain AISI 8640 steel drills bits, used to bore holes in rocks. This paper presents the tooling to obtain the piece, together with the procedure used for testing, comparing the force found in practice to computer simulation. It was found that the process proposed saved 3.5% of materials, and presented a 13% increase in piece hardness in the quenched and tempered state, compared to the piece produced conventionally.

This research look for alternatives to the fabrication of solar energy collector panels using new technologies: Incremental Sheet Metal Forming and Friction Stir Welding with a 3-axis CNC machine. This process innovation allows great flexibility, making the low volume production feasible, with high level of customisation.

The manufacturing of the gear profile by Metal Forming is widely used in industry due to its quality and production capability. Direct cold extrusion has this characteristic and with support of peripheral technologies allows the development of asymmetric parts with complex geometry and near net shape. These resources, added with the great experience of a Brazilian forging company with strong presence in the cold forging market, allowed to develop a cold extrusion process to produce spur gears using the low carbon steel alloy described as SAE 10B22. The goal of this study was to develop the whole process, precision tooling project and manufacture as well as the experimental availability of the process. The tools were manufactured with high speed steel AISI M2 having a hardness in a range from 61 up to 63 HRc. The shrink rings were manufactured using steels with more toughness, such as S1 and H13. The application of shrink rings for the prestressing of tooling was evaluated using two different methods. The first one is using conventional shrink rings with tool steel, while the second is the stripwinding concept developed by the company STRECON.