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In the present study, the wear behaviour of two aluminium alloys (AA-5754 and AA-5083) is analysed where these have been previously processed by severe plastic deformation (SPD) with equal channel angular pressing (ECAP). In order to achieve the objectives of this study, several disks made of these alloys are manufactured by isothermal forging from different initial states. The microstructures of the initial materials analysed in this study have different accumulated deformation levels. In order to compare the properties of the nanostructured materials with those which have not been ECAP-processed, several disks with a height of 6 mm and a diameter of 35 mm are manufactured from both aluminium alloys (that is, AA-5754 and AA-5083) isothermally forged at temperatures of 150 and 200 &deg, C, respectively. These thus-manufactured disks are tested under a load of 0.6 kN, which is equivalent to a stress mean value of 18 MPa, and at a rotational speed of 200 rpm. In order to determine the wear values, the disks are weighed at the beginning, at 10,000 revolutions, at 50,000 revolutions and at 100,000 revolutions, and then the volume-loss values are calculated. This study was carried out using specific equipment, which may be considered to have a block-on-ring configuration, developed for testing in-service wear behaviour of mechanical components. From this, the wear coefficients for the two materials at different initial states are obtained. In addition, a comparison is made between the behaviour of the previously ECAP-processed aluminium alloys and those that are non-ECAP-processed. A methodology is proposed to determine wear coefficients for the aluminium alloys under consideration, which may be used to predict the wear behaviour. It is demonstrated that AA-5754 and AA-5083 aluminium alloys improve wear behaviour after the ECAP process compared to that obtained in non-ECAP-processed materials.

Over the last few years there has been an increasing interest in the study and development of processes that make it possible to obtain ultra-fine grained materials. Although there exists a large number of published works related to the improvement of the mechanical properties in these materials, there are only a few studies that analyse their in-service behaviour (fatigue and wear). In order to bridge the gap, in this present work, the fatigue and wear results obtained for connecting rods manufactured by using two different aluminium alloys (AA5754 and AA5083) previously deformed by severe plastic deformation (SPD), using Equal Channel Angular Pressing (ECAP), in order to obtain the ultrafine grain size in the processed materials are shown. For both aluminium alloys, two initial states were studied: annealed and ECAPed. The connecting rods were manufactured from the previously processed materials by using isothermal forging. Fatigue and wear experiments were carried out in order to characterize the in-service behaviour of the components. A comparative study of the results was made for both initial states of the materials. Furthermore, Finite Element Modelling (FEM) simulations were used in order to compare experimental results with those obtained from simulations. In addition, dimensional wear coefficients were found for each of the aluminium alloys and initial deformation states. This research work aims to progress the knowledge of the behaviour of components manufactured from ultrafine grain materials. The authors of this present research work acknowledge the support given by the Spanish Ministry of Economy, Industry and Competitiveness (former Spanish Ministry of Economy and Competitiveness) through the Research Project DPI2013-41954-P.

This present research work deals with the development of ultrafine grained cams obtained from previously ECAP (Equal Channel Angular Pressing)-processed material and manufactured by isothermal forging. The design and the manufacturing of the dies required for the isothermal forging of the cams are shown. Optimization techniques based on the combination of design of experiments, finite element and finite volume simulations are employed to develop the dies. A comparison is made between the mechanical properties obtained with the cams manufactured from material with no previous deformation and with those from previously SPD (Severe Plastic Deformation)-processed material. In addition, a comparative study between the experimental results and those obtained from the simulations is carried out. It has been demonstrated that it is possible to obtain ultrafine grained cams with an increase of 10.3% in the microhardness mean value as compared to that obtained from material with no previous deformation. The authors of this present research work acknowledge the support given by the Spanish Ministry of Economy and Competitiveness through the Research Project DPI2013-41954-P.

In this research study, a comparative examination on the mechanical properties of AA6063 has been carried out after having been processed by isothermal forging, using plane-shape dies and starting from different initial deformation states. It introduces the novelty of employing experimental data obtained from the isothermal forging so as to model the flow rules of AA6063 processed by equal channel angular pressing taking temperature into account and using artificial neural networks to this end. Subsequently, these flow rules are employed to model the behaviour of AA6063 by means of finite element simulation. Furthermore, a validation of the experimental results is made with those obtained from the simulations using the flow rules attained with the neural networks. It is shown that it is possible to achieve higher precision than with traditional fitting methods of flow rules. In addition, this study presents the novelty of carrying out a comparative study between different starting material states, prior to forging, including among these material previously processed by the severe plastic deformation process, which is referred to as equal channel angular pressing. Moreover, the experimental results obtained when processing the aluminium alloy by equal channel angular pressing are compared to those states, which correspond to the traditional way of working on aluminium alloys, which can be quenched and aged for the purpose of improving their mechanical properties.

This present research work deals with the design by finite element method (FEM) of the dies required for the isothermal forging of a Francis turbine blade taking into account that the starting material has been previously nanostructured through severe plastic deformation by equal channel angular extrusion. This nanostructured material possesses improved mechanical properties and hardness, better forgeability, and, under specific conditions, a superplastic behavior. Once this material is obtained, its flow rule has been determined through compression tests at different temperature values along with its subsequent fitting with artificial neural networks. Later on, these rules will be employed in the FEM simulations included in this present study. Furthermore, the results of the processing of these materials are shown comparing the properties of the mechanical components after their isothermal forging at different temperature values both with predeformed and non-predeformed material. This work is at the cutt...

In this present research work, a study on the design and the manufacturing of Francis turbine blades with submicrometric microstructure from AA1050 has been carried out by means of combining equal channel angular extrusion (ECAE/ECAP) and isothermal forging. The starting material used is previously processed by the severe plastic deformation (SPD) process named ECAE. In spite of the fact that, over the last few years there has been a great deal of interest in SPD materials, there have been scant industrial applications made of them. As will be shown in this research work, it is possible to significantly increase the mechanical properties of the AA1050, compared to that obtained by conventional manufacturing processes, as well as to obtain a submicrometric microstructure in the so-obtained parts. Therefore, this present study aims to demonstrate the viability of obtaining mechanical components at moderate forging temperature values and with higher mechanical properties than those obtained by conventional forging or from isothermal forging processes.

Aluminum foams are porous metallic materials which possess an outstanding combination of physical and mechanical properties such as: a high rigidity with a very low density. In this present research work, a study on the upsetting of an aluminum foam (with a density = 0.73 g/cm3) is carried out by employing different compression velocity values. From the results obtained, it is possible to determine the material flow stress for its subsequent use in finite element simulations (FEM). Once the material flow stress has been determined, it will be employed in order to analyze the conformability of several parts by FEM.

Incremental Sheet Forming (ISF) process may be classified within the field of sheet metal forming processes, more specifically in the asymmetric incremental deformation process. Some studies have been carried out on the influence of different parameters in the process. However, there are few publications that evaluate the influence of these parameters using design of experiments by finite element modelling. This study provides a better understanding of the process, which will enable an optimization of the ISF process and its comparison with other metal forming processes. Furthermore, this study will be the basis for determining the development of the equipment necessary to carry it out.

This work presents a study related to the achievement of forged billets using plane-shape dies from a 5083 aluminium alloy previously processed by the Severe Plastic Deformation (SPD) process known as ECAE (Equal Channel Angular Extrusion). ECAE is one of the most well-known SPD processes and in this study, it is going to be employed in order to obtain nano-structured starting material. Changes in the microhardness and in the microstructure of the isothermally upset-forged billets have been studied after having been processed by ECAE. Isothermal upsetting tests were performed at different values of strain, temperature and compression velocity. Furthermore, optical and scanning electron microscopy (SEM) techniques have been utilised in order to analyse the final microstructure. As will be shown in this present study, ECAE improves the forgeability of AA-5083 and, after the upsetting process, submicrometric grain size material is attained.

The Equal Channel Angular Extrusion or Pressing (ECAE/ECAP) process has been developed over these last years in order to obtain nanostructured materials by means of severe plastic deformation. These applications have been mainly focused on light alloys while its application to iron and steel has not been so common. This is due to the difficulties that their ECAE processing implies, as much higher values for the processing force are required. In this present study, the results achieved when Armco-Fe is processed by ECAE at room temperature are shown. In addition, a comparative study on the variation in the mechanical properties (yield stress, ultimate tensile strength, and elongation at break) is shown when different thermal treatments are employed. Specific combinations are also shown of the thermal treatments which lead to a higher value of elongation and mechanical strength in relation to the starting material. Furthermore, an analysis of the obtained results is made by optical and scanning electron mic...

The most important difficulties when the behaviour of a part that is subjected to external mechanical forces is simulated deal with the determination of both the material thermo-mechanical properties and its boundary conditions. The accuracy of the results obtained from the simulation is directly related to the knowledge of the flow stress curve. Therefore, the determination of a material flow rule which is valid for both a wide temperature range and different initial deformation conditions in the starting material presents a great deal of interest when simulation results close to the experimental values are required to be obtained. In this present study, a novel flow stress curve is proposed that is able to accurately predict the behaviour of both materials with no previous accumulated strain and materials that have been previously subjected to severe plastic deformation processes. Moreover, it is possible to use it both for hot and cold working. The results are analysed in a wide test temperature range, which varies from room temperature to 300 °C, and from material previously processed by angular channel extrusion or with no previous strain accumulated. It is shown that the flow rule proposed is effective to model the material behaviour in a wide temperature range and it makes it possible to take the recrystallization phenomena that appear in previously deformed materials into account. In addition, the results obtained are compared with those predicted by other flow rules that exist in the prior literature. Furthermore, the study is complemented with finite element simulations and with a comparison between simulation and experimental results. The authors acknowledge the support given by the Spanish Ministry of Economy and Competitiveness under the research project DPI2013-41954-P.

In this research work, a study on the mechanical properties of isothermal forging for connecting rods is made from previously ECAP (Equal Channel Angular Pressing)-processed AA1050 and AA5083 aluminium alloys. This severe plastic deformation (SPD) process is used in order to achieve a starting material with a submicrometric structure, thus improving the mechanical properties of the part. In this study, the design and the experimentation process is shown, where this involves the design stage by finite element simulations, the experimental tests and the use of metallographic techniques for the required properties to be analysed. Itis observed thatthere is an improvementin the mechanical properties when the starting material is ECAP-processed before carrying out the isothermal forging. This improvement consists in an increase of 20% in the hardness of the final connecting rod which also possesses a microstructure grain size of 500 nm. To come to these conclusions,the results obtained with the connecting rods manufactured by isothermal forging from previously ECAP-processed material are compared with those conventionally manufactured. Therefore,the feasibility and the advantages ofthe industrialmanufacturing ofmechanical components by isothermal forging from ECAP-processed material are demonstrated here as mechanical properties are achieved, as well as a better flow of the material and at a lower forging temperature. In the existing bibliography, there are no research works dealing with the manufacturing of connecting rods from ultra-fine grained material and that is the reason why this present study is considered to be of scientific and technological interest, and therefore, it may be considered to be at the frontline of current knowledge. The authors of this present research work acknowledge the support given by the Ministry of Economy and Competitiveness from Spain, through the Research Projects DPI2010-18941 and DPI2013-41954-P.

Assessing the damage produced in plastic deformation processes permits the optimum manner to shape a material that could avoid any cracks from appearing. In this present research work, the absolute critical damage in the following aluminium alloys: AA5754, AA5083 and AA3103 is to be determined. In order to do this, compression tests between plane-shape dies will be performed for the abovementioned alloys at a temperature range which varies from 25 °C to 300 °C and using Cockroft–Latham's prediction model. Furthermore, the results obtained by finite volume simulations will be compared with those obtained by experimental tests with isothermal upsetting. Given that in these last few years there has been a growing interest in obtaining mechanical components from submicrometric and/or nanometric structure materials which have been previously-processed by severe plastic deformation (SPD), this present research work deals with the determination of absolute critical damage for the abovementioned alloys once they have been ECAP (Equal Channel Angular Pressing) processed. This is considered to be of interest since it could allow the prediction of optimal processing conditions in advance. The authors of this present research work acknowledge the support given by the Spanish Ministry of Economy and Competitiveness through the Research Project DPI2013-41954-P.

ECAE process is a novel technology which allows us to obtain materials of sub-micrometric and/or nanometric grain size as a result of accumulating very high levels of plastic deformation in the presence of high hydrostatic pressure. This avoids the material being fractured and permits very high values of plastic deformation to be obtained (ε>>1). Therefore, these nanostructured materials can be used as starting materials for other manufacturing processes such as: extrusion, rolling and forging among others; with the advantage of providing nanostructure and hence improving the mechanical properties. In this present study, forging by finite element of materials that have been previously predeformed by ECAE is analysed. MSC.MarcTMsoftware will be employed with the aim of analysing the possibility of manufacturing mechanical components (spur gears) from materials nanostructured by ECAE.

Equal channel angular extrusion or pressing (ECAP) is a process used to impart severe plastic deformations (SPD) (e << 1) to materials with the aim of improving their mechanical properties by reducing the grain size. In this study, an analytical modeling of the ECAP processing force required, taking circular cross-section for ECAP dies into consideration, is developed where non-strain hardening materials are processed. To obtain the equation that relates the geometry and required force, the upper bound method was used after taking an appropriate and admissible field into consideration. In addition, a comparison between analytical methods and experimental results was made. In order to perform the experimental tests, an F-1050-AA (F means as fabricated) was selected and processed at room temperature. This alloy has a yield stress of 70 MPa and an insignificant strain hardening. The experimental results obtained agree closely with those provided by the analytical formulation. With this study, it is possible to have an analytical approach to the required force for performing the ECAP process. This could help scientists and practical engineers involved in SPD processes such as ECAP, to optimize ECAP dies and the process itself thanks to the knowledge of the analytical expressions of the required force.

Recent studies have shown that severe plastic deformation processes (SPD) improve the mechanical properties of the processed parts. Some of the most outstanding SPD processes are as follows: High Pressure Torsion (HPT), Repetitive Corrugation and Straightening (RCS), Cyclic Extrusion Compression (CEC), Accumulative Roll Bonding (ARB), Conform and Continuous Combined Drawing and Rolling (CCDR), among others, but the most well-known is Equal Channel Angular Extrusion or Pressure (ECAE/ECAP). The aim of these processes is to introduce high values of deformation inside the parts in order to reduce the grain size and thus to improve the mechanical properties of the starting material. The study of the damage imparted to an AA-6082 alloy is made in the present work. This alloy is received as cast and it is quenched at a temperature of 530 °C during 4 hours in order to be processed by ECAE at room temperature using different geometries of the dies. The imparted damage is also studied by using FEM simulations.

En el presente trabajo se ha realizado un estudio de la modificación de las propiedades mecánicas de la aleación de aluminio AA6060 F, al ser deformada mediante deformación plástica severa empleando el proceso de extrusión en canal angular (ECAE). Asimismo, se ha efectuado un estudio del efecto del envejecimiento artificial sobre la modificación de dichas propiedades mecánicas. Para ello, se han realizado tratamientos térmicos a diferentes temperaturas y tiempos de permanencia, efectuando mediciones de dureza, ensayos de tracción, ensayos con péndulo Charpy y técnicas de revelado metalográfico, para conocer los comportamientos mecánicos y el estado del material. Existe un elevado número de publicaciones, que han analizado el efecto de tratamientos térmicos de envejecimiento en aleaciones de la serie 6000. Sin embargo, la aleación AA6060 no ha sido tan ampliamente estudiada. Por ello, en este trabajo se parte de una aleación comercial AA6060 en estado de bruto de colada, lo cual no ha sido estudiado hasta la fecha. In the present work, a study on the modification of the mechanical properties of the aluminium alloy AA6060 F has been made when severe plastic deformation is applied to it through Equal Channel Angular Extrusion (ECAE). Moreover, a study about the effect of the artificial aging on the modification of such mechanical properties has been carried out after having processed the material by ECAE. In order to do this, thermal treatments at different values of temperature and holding time have been performed. Hardness, tensile tests and Charpy impact test, along with metallographic techniques, have been carried out in order to analyse the mechanical behaviour and the state of the material. In spite of the existence of several studies that have analysed the effect of aging thermal treatments on 6000 aluminium alloys, such studies are focused on laboratory alloys with industrial compositions not very usual. Therefore, in the present work, the employed starting material is a commercial alloy as-cast, which has not been studied up to now. Los autores del presente estudio agradecen el apoyo dado por el Ministerio de Ciencia e Innovación (Proyecto de investigaciónMAT2006-14341-C02-02).

In this study, the influence of the die geometry on the introduced damage of the processed parts by ECAE is studied. It will be shown experimentally and by FEM simulations that the die geometry greatly influences the imparted damage, if the die geometry is not selected adequately. This could lead to obtain processed materials which could be useless for posterior mechanical applications because of cracks nucleated inside of them, which will decrease the mechanical properties such as fatigue resistance and formability among others. Several FEM models have been solved in order to obtain a mathematical model to predict the influence of the die geometry. Moreover, several parts have been processed using different die geometries in order to determine the damage within the processed material experimentally and also to validate FEM simulations. A 5083 aluminium alloy in (O) state, which means that has been fully annealed, has been selected and different die geometries have been manufactured for processing this aluminium alloy.

Equal channel angular extrusion (ECAE) is a process used to impart severe plastic deformation within the material billet. This has a great deal of interest because of the improvement achieved in the mechanical properties of the material to be processed. In this study, a finite element method (FEM) analysis has been used in order to find out how the geometrical parameters of the ECAE dies and the part affect the punch force. This is important in order to predict the force required to perform the process accurately. By solving several finite element models with different geometries, a mathematical model for the extrusion pressure was obtained, and it has been possible to study the influence of the geometry on the processing force. From this, a better die design can be made. FEM modelling has been validated by comparison with experimental results. This comparison has shown a good agreement between both of them (a difference lower than 8 per cent). Moreover, the error obtained with an analytical analysis based on the upper bound method has been determined by comparison of analytical and FEM results. This has shown that the difference between analytical and FEM results was less than 9 per cent.

As is well-known, teaching of the computer-aided technologies is gaining more and more importance in the field of Manufacturing Processes Engineering. One such example is the growing tendency to employ computers in the simulation of material removal processes (CAM). In this study, a methodology proposed by the Manufacturing Processes Engineering Section in order to teach material removal processes is shown. This methodology is put into practice by employing one CAM software such as Surfcam® and is applied to the teaching subjects given by the previously-mentioned Section belonging to the Public University of Navarre. Due to the length of the practice manual developed for this purpose, which covers turning, milling and EDM processes, the present work has only been focused on the use of Surfcam® in the first case.

Equal channel angular extrusion or pressing (ECAE or ECAP) is a process used to introduce severe plastic deformations (SPD) to processed materials with the aim of improving their mechanical properties by reducing the grain size. In this work a study of the required force for performing the ECAE process, which takes into account the ECAE dies proposed by Luis [Luis, C.J., 2004a. On the correct selection of the channel die in equal channel angular extrusion processes. Scripta Mater. 50, 387–393] is developed. These die geometries improve the deformations attained in the traditional ECAE dies and they allow a correct flow of the material, a complete filling of the channels and reduce the damage introduced inside the part, increasing the attained strain. By using the upper bound method the required force for performing the ECAE process in function of all the geometric parameters is determined. Although some works exist that have applied the upper bound method to analyse the ECAE process, they consider plane strain conditions. This works presents an analysis of required forces in the ECAE process considering a three dimensional geometry and hence attained results are more reliable than those obtained by assuming plane strain conditions.

Pure commercial Cu of 99,98 wt % purity was processed at room temperature by Equal- Channel Angular Pressing (ECAP) following route Bc. Heavy deformation was introduced in the samples after a considerable number of ECAP passes, namely 1, 4, 8, 12 and 16. A significant grain refinement was observed by transmission electron microscopy (TEM). Tensile and microhardness tests were also carried out on the deformed material in order to correlate microstructure and mechanical properties. Microhardness measurements displayed a quite homogeneous strain distribution. The most significative microstructural and mechanical changes were introduced in the first ECAP pass although a gradual increment in strength and a slight further grain refinement was noticed in the consecutive ECAP passes.

Trabajo presentado a The Manufacturing Engineering Society International Conference, MESIC 2015 (Barcelona) In the present study, the design of the dies required for the isothermal forging of a cam is analysed by finite volume method. Specifically, cams are of great importance in automotive industry, where a lower weight and an improvement in the lubrication or in the materials to be in contact lead to a significant reduction in the fuel cost. The flow stress curves of one Al-Mg alloy were firstly determined by using compression tests. Once these flow stress curves were obtained, FV simulation was employed. In the forging process, the optimum die configuration has been selected. To this end, several aspects have been taken into account such as the force required for the forging, the correct die filling, the introduced plastic strain and the damage imparted to the billet. The authors acknowledge the support given by the Spanish former Ministry of Economy and Competitiveness under the research project DPI2013-41954-P.

Trabajo presentado a The Manufacturing Engineering Society International Conference, MESIC 2015 (Barcelona) This present research work deals with the analysis of the design of different specimen geometries so that by finite volume simulations, the appearance of cracks may be predicted in the case of forging processes. To this end, each of the geometries selected are studied by means of compression tests between plane shape dies in the same conditions (T = 25 ºC). On the one hand, a value for the critical damage value is obtained by applying the Cockroft-Latham’s criterion and on the other hand, a damage distribution along all the specimen volume with the aim of defining a specimen which shows the most likely place for the crack to appear. This crack location may be also determined through visual inspection with the aim of being able to evaluate this experimentally in the near future. The authors acknowledge the support given by the Spanish former Ministry of Economy and Competitiveness under the research project DPI2013-41954-P.

Over these last few years, there has been a growing interest in developing mechanical components from submicrometric materials due to the significant improvement that these materials present compared to their original state. This present research work deals with the study of the mechanical properties of a connecting rod isothermally forged from different starting materials. These materials are as follows: annealed aluminum alloy (AA) 5754, the same alloy previously deformed through equal channel angular pressing (ECAP) and a third case where the previously ECAP-processed material is subjected to a recovery heat treatment. A comparison is made between finite volume (FV) simulations and experimental tests with respect to hardness, plastic strain and forging force. Furthermore, the improvement in the mechanical properties of the connecting rod forged from predeformed material is evaluated in comparison to the connecting rod forged with annealed material. The microstructure of both cases is also compared at the end of the manufacturing process. The authors acknowledge the support given by the Ministerio de Ciencia e Innovación (Spain) (Research Project: DPI2013-41954-P.

Ultrafine grained materials have a great deal of both scientific and technological interest because they allow outstanding properties to be obtained. An improvement in the mechanical strength and in the ductility and a better fatigue behaviour are properties to be expected with these materials. However, in spite of the great number of scientific publications that deals with the mechanical property improvement, the number of practical applications of these materials is scant. In this present research work, equal channel angular pressing (ECAP) is used as a severe plastic deformation process (SPD) to obtain billets which are subsequently isothermally forged to obtain a connecting rod with submicrometric grain size. The optimization of the design process is shown as well as the die design. The objective variables to be fulfilled are the correct filling of the die and the required force to obtain the part. Moreover, a comparison is also included between the mechanical properties thus obtained and those obtained with traditional methods. Moreover, optical and SEM micrographs are also included in this research work. The authors of this present research work acknowledge the support given by the Ministry of Science and Innovation from Spain (now Ministry of Economy and Competitiveness), through both the Research Project DPI2010-18941 and the Research Project DPI2013-41954-P.

In this work, the strain field attained by using a severe plastic deformation (SPD) process called equal channel angular extrusion (ECAE) is studied by the finite element method (FEM). The three-dimensional model with circular section includes shear friction between the part and the die, the material strain hardening behaviour and a rigid-deformable contact between the billet and the die. In the ECAE process the part is extruded through two channels with similar diameter that intersect at an angle. When the extrusion process has been performed, the processed material remains it cross section, so there is not any geometric limitation to achieve the desired plastic strain. There are different ways of processing the material by using the ECAE process; those ways of processing are called routes. In this work two passages of route C have been simulated. Using route C means that the billet has been rotated 180º between each passage. Deformations imparted to the processed material have been calculated and a comparison with experimental results has been carried out.

Equal channel angular extrusion or pressing (ECAE or ECAP) is a process used in order to impart severe plastic deformations to processed materials with the aim of improving their mechanical properties by reducing the grain size. The grain size reduction leads to mechanical properties improvement. In the present study, a new die configuration is proposed for the ECAE process. The advantage of this die geometry is that it allows us to obtain higher plastic strain in each ECAE passage than traditional ECAE dies. It is important to optimize the die geometry, as the main aim of the ECAE process is to impart severe plastic deformations to the processed materials. Consequently, the higher the deformation, the better the improvement on the mechanical properties of the processed materials. In order to determine how variations on geometry affect the plastic strain of the processed materials finite element modeling (FEM) is used. Both analytical and FEM methods will allow us to affirm that by using this new die configuration it is possible to achieve higher deformation values per ECAE passage.

The knowledge of stresses and temperature in equal channel angular extrusion (ECAE) process is very important, in order to deform the material under the optimal thermo-mechanic conditions and to achieve the desired mechanical properties improvement in the processed material. As one of the main aims of the process is to reduce the grain size of the processed material, by shear deformation, the process temperature should be maintained under control. In this work, temperatures inside both the die and billet are studied. Also, the temperature increases during the process, as a consequence of the deformation, the friction and the heating of the resistors are calculated for different operation conditions by using finite element method (FEM).

Equal channel angular extrusion (ECAE) is an innovative technique for developing ultrafine-grained microstructures first developed by Segal et al in 1981 in the former Soviet Union. The ECAE method consists of two channels that intersect at an angle, generally comprised between 90° and 135°. The deformation is produced by shear as the billet is extruded through the channels. One of the geometrical properties of the process is that the cross-section of the billet remains constant and so, it is possible to repeat the process over many cycles. Therefore, very high plastic strains can be accumulated in the billet. Thus, the ECAE process allows us to produce ultrafine-grained materials and hence to improve the mechanical properties of the material. This work presents a study of the mechanical and optical properties of the AA5083 processed by equal channel angular extrusion. Vickers microhardness and tensile tests were carried out after processing the AA5083 up to N = 5 at room temperature. The improvement obtained in mechanical properties is shown.

Wire drawing is one of the most commonly used processes for obtaining wire used in mechanical applications such as: rivets, screws, welding wires, etc. In this work, several analytical methods have been employed in order to obtain the forces, energies, stresses and strains that are involved in the process. A comparative study between analytical methods and FEM results is presented, considering hardening strain materials. The material selected to carry out those analyses was an aluminium alloy AA-5083, whose flow stress was determined by an appropriate tension test. The geometric property of axisymmetry has been used in order to reduce the computational cost in the finite element simulations, and to simplify the equations for the rest of the methods introduced. The energies involved in wire drawing processes are also determined. Moreover, energies involved in the process are studied for both strain hardening and non-strain hardening materials.

In the last years, new severe plastic deformation (SPD) processes have been developed in order to produce very high values of deformation in the materials to be processed, with only small changes in the size of parts. This is not possible through conventional thermo-mechanical processes, in which the increase up to the above-mentioned values of deformation is usually associated with a change in their geometry. As is well-known, with enough accumulation of plastic deformation, a new submicrometric or even nanometric grain structure substitutes the former. Given that the grain size in metallic materials has a great deal of influence on their mechanical properties, the refinement of this grain size provides enormous technological advantages. For instance, at low values of temperature, a fine grain size can increase mechanical strength, hardness, fracture toughness and the material fatigue limit. Furthermore, at high values of temperature, the alloys with an ultrafine grain size may exhibit a superplastic behaviour and thus, the ability to undergo very high values of deformation with no damage to the material. The continuous combined drawing process in angular channels (CCDR) is a new concept of severe plastic deformation process (SPD), developed by researchers belonging to the Public University of Navarre and based on the patent (ES 2224787). In the present work, finite element analysis will be employed in order to study not only the strain distribution in the processed materials but also the homogeneity of the introduced strain. Moreover, experimental results will be compared to that obtained by using FEM. With the present work, it will be shown that it is feasible to achieve a process with possible industrial application, making the continuous processing of metallic materials in angular channels by SPD possible.

This work presents a study related to the achievement of a nanometric structure in AA3103, employing severe plastic deformation processes (SPD), in this case equal channel angular pressing (ECAP). The changes in the mechanical properties and in the microstructure of AA3103 were studied after being processed by ECAP. Subsequently, scanning electron microscopy was used to determine the evolution of the microstructure after different thermal treatments on the material processed by this severe plastic deformation process. Furthermore, a more profound knowledge of the changes in the mechanical properties of this aluminium alloy was obtained. It was demonstrated that with different appropriate combinations of thermal treatments and ECAP processing, it is possible to significantly improve the mechanical properties through obtaining submicrometric grain size structures. The authors of the present study acknowledge the support given by the Government of Navarre (Project EUROINNOVA NANOCONS-IIM10784.RI1).

This research work deals with the manufacturing of blades for a Francis turbine with a submicrometric structure through the isothermal forging of a heat-treatable aluminum alloy that has been previously processed by angular channel extrusion. In addition, mechanical properties and microstructure of these same blades are analyzed. A comparative study is also carried out between the properties obtained in the forged blades from the alloy previously deformed through angular channel extrusion and those obtained by employing two other isothermal forging processes of this alloy which mean utilizing different process stages. Moreover, a modeling by finite element about the isothermal forging process of the blades is performed using flow rules obtained from compression tests on these alloys at different temperatures. In this way, a much higher degree of accuracy is achieved in the results compared with that obtained through traditional approaches. With this present study, it is intended to make some progress in the development of nanostructured mechanical components with the aim of demonstrating the feasibility of their manufacturing and achieving an improvement in their mechanical properties.

Over these past few years, there have been a large number of technical papers published related to the problem of improving the mechanical properties of materials obtained through severe plastic deformation. Nevertheless, the number of technical papers dealing with improvement in the mechanical properties of mechanical components manufactured from submicrometric grain size material has not been so proficient. Therefore, in this present research work, a straight blade has been manufactured starting from AA-5083 previously processed by ECAE twice (N2) with route C.This material will be manipulated so as to be isothermally forged at different temperature values.This present research work shows the results that are inherent in an improvement in themechanical properties and the microstructure achieved in the thus obtained components, compared with the starting material. In addition, the optimum forging temperature to achieve these components will be determined. As shown in this research work, it is possible to obtain submicrometric grain size mechanical components with a higher mechanical strength than those obtained in nonultrafine grained materials. The originality of this research work lies in the manufacturing of actual mechanical components from ECAE processed material and the analysis of their properties. The authors acknowledge the support given by the Spanish former Ministry of Science and Innovation (now Ministry of Economy and Competitiveness) under the Research Project DPI2010-18941.

The manufacturing of a functional hollow mechanical element or ring of the AA5083 alloy previously equal channel angular extrusion (ECAE) processed, which presents a submicrometric microstructure, is dealt with. For this purpose, the design of two isothermal forging dies (preform and final shape) is carried out using the design of experiments (DOE) methodology. Moreover, after manufacturing the dies and carrying out tests so as to achieve real rings, themechanical properties of these rings are analysed as well as their microstructure. Furthermore, a comparison between the different forged rings is made fromECAE-processedmaterial subjected to different heat treatments, previous to the forging stage. On the other hand, the ring forging process ismodelled through the use of finite element simulation in order to improve the die design and to study the force required for the isothermal forging, the damage value, and the strain thematerial predeformed by ECAE has undergone.With this present research work, it is intended to improve the knowledge about the mechanical properties of nanostructured material and the applicability of this material to industrial processes that allow the manufacturing of functional parts. The authors acknowledge the support given by the Spanish “Ministry of Science and and Innovation” (now “Ministry of Economy and Competitiveness”) through the Research Project DPI2010-18941.

The ECAE process is a novel technology which allows us to obtain materials with sub-micrometric and/or nanometric grain size as a result of accumulating very high levels of plastic deformation in the presence of a high hydrostatic pressure. This avoids the fracture of the material and allows us to obtain very high values of plastic deformation (ϵ >>1). Therefore, these nano-structured materials can be used as starting materials for other manufacturing processes such as: extrusion, rolling and forging, among others; with the advantage of providing nanostructure and hence, improved mechanical properties. In this present work, the forging by finite element method (FEM) of materials that have been previously processed by ECAE is analyzed. MSC. MarcTM software will be employed with the aim of analyzing the possibility of manufacturing mechanical components (spur gears) from materials nano-structured by ECAE.

Recent studies have shown that Severe Plastic Deformation (SPD) processes improve the mechanical properties of the parts processed by a reduction in the grain size. Equal Channel Angular Extrusion (ECAE) is one of the most well-known SPD processes. A study on the force and the strain after two ECAE passages is made, along with the damage imparted to AA-6082, by means of experiments and Finite Element Simulations (FEM). The aim of this research is to make a comparative study between experimental results and those obtained by FEM in order to verify the feasibility of these FEM simulations. In addition to this, it is intended to analyze the homogeneity obtained in the strain values after two ECAE passages through route C.

Severe plastic deformation processes have a great deal of importance because of the improvement in mechanical properties of the processed parts as a consequence of the grain size reduction in the material due to the accumulation of deformation. One of the main severe plastic deformation (SPD) processes is called the equal channel angular extrusion (ECAE). Although a large amount of studies, which deal with experimental analysis of processed parts exist, few studies dealing with the force required to perform the process have been developed. In this study, an analytical modeling of the force required to perform the ECAE process has been developed using the upper bound method (UBM). The analytical equations developed take into account the material strain hardening and the ECAE dies with circular cross-section. Moreover, the experimental tests have been performed and the extrusion force has been measured. The UBM and experimental results have been compared showing a great deal of agreement.

Equal channel angular extrusion (ECAE) or pressing is a process used to introduce severe plastic deformations to processed materials with the aim of improving their mechanical properties by reducing the grain size. At present, there are no analytical studies that have considered strain hardening materials in order to determine the required force to carry out the process. All the existing papers have only considered nonstrain hardening materials. Furthermore, all those studies have been done by considering plane strain conditions. In this work, an upper bound analysis of the required force for performing the ECAE process is made by considering a full three-dimensional geometry with a rectangular cross section. From this analysis, the influence of the geometric and the material parameters is studied by considering both friction and strain hardening materials. By using the upper bound method, an analytical formulation was obtained and the influence of all the parameters was determined. With this work, it is possible to have a wider knowledge of the influence of the main affecting parameters in the ECAE process and to optimize them.

In this present study, both the design and the optimal manufacturing conditions for processing a straight blade by isothermal forging are shown. The starting material has been previously deformed by a severe plastic deformation (SPD) process known as equal channel angular extrusion (ECAE). As is well-known, the ECAE process is a technology which allows us to obtain materials with sub-micrometric grain size. These nanostructured materials can be employed afterwards as initial materials for other manufacturing processes. The use of these ultra fine grain sized materials (UFG) provides improved mechanical properties such as: greater hardness and mechanical strength, among others. In this present study, FEM simulations of the isothermal forging of an AA5083 previously deformed by ECAE will be carried out. The total equivalent plastic strain, the damage and the forces required to carry out the isothermal forging of this nanostructured aluminium alloy will be determined.