Open Access
Modelización y análisis del proceso de forja de componentes mecánicos obtenidos a partir de material nanoestructurado
(2013) Salcedo Pérez, Daniel; Luis Pérez, Carmelo Javier; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
This Ph. D. Thesis deals with the feasibility of manufacturing mechanical components with submicrometric and/or nanometric structure by means of materials previously SPD processed with ECAE. To this end, a preliminary study on the assessment of the previously ECAE processed AA5083 flow rules is made as a function of temperature and forging velocity. Subsequently, the design of the dies required for the forging of this material is carried out and experimental tests are performed with the equipment belonging to the Public University of Navarre in order to analyse the mechanical properties of the manufactured mechanical elements. In addition, finite element simulations of both traditional forging and isothermal forging are carried out comparing these results with those obtained in the real tests. It is shown that a high degree of accuracy is achieved in the results obtained. Furthermore, a comparative study is made between the traditional forging and the isothermal forging when different mechanical components are manufactured both annealed or previously ECAE processed. With the present Ph. D. Thesis, a complete and deep study is made on the forging of previously SPD processed material with ECAE. This widens the knowledge about this kind of materials and it demonstrates the feasibility of obtaining mechanical elements with submicrometric and/or nanometric structure.
Open Access
Comparative study of the damage attained with different specimens by FEM
(Elsevier, 2015) Fuertes Bonel, Juan Pablo; Luri Irigoyen, Rodrigo; Luis Pérez, Carmelo Javier; Salcedo Pérez, Daniel; León Iriarte, Javier; Puertas Arbizu, Ignacio; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
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.
Open Access
Analysis of tribological properties in disks of AA-5754 and AA-5083 aluminium alloys previously processed by equal channel angular pressing and isothermally forged
(MDPI, 2020) Luis Pérez, Carmelo Javier; Luri Irigoyen, Rodrigo; Puertas Arbizu, Ignacio; Salcedo Pérez, Daniel; León Iriarte, Javier; Fuertes Bonel, Juan Pablo; Ingeniería; Ingeniaritza
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 °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.
Open Access
Analysis on the manufacturing of an AA5083 straight blade previously ECAE processed
(Hindawi, 2013) Salcedo Pérez, Daniel; Luis Pérez, Carmelo Javier; Puertas Arbizu, Ignacio; León Iriarte, Javier; Fuertes Bonel, Juan Pablo; Luri Irigoyen, Rodrigo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
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.
Open Access
Study and optimization of the punching process of steel using the Johnson-Cook damage model
(MDPI, 2024) Claver Alba, Adrián; Hernández Acosta, Andrea; Barba Areso, Eneko; Fuertes Bonel, Juan Pablo; Torres Salcedo, Alexia; García Lorente, José Antonio; Luri Irigoyen, Rodrigo; Salcedo Pérez, Daniel; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2
Sheet metal forming processes are widely used in applications such as those in the automotive or aerospace industries. Among them, punching is of great interest due to its high productivity and low operating cost. However, it is necessary to optimize these processes and adjust their parameters, such as clearance, shear force or tool geometry, to obtain the best finishes and minimize crack generation. Thus, the main objective of this research work is to optimize the punching process to achieve parts that do not require subsequent processes, such as deburring, by controlling the properties of the starting materials and with the help of tools such as design of experiments and simulations. In the present study, tensile tests were performed on three steels with different compositions and three sample geometries. The information obtained from these tests has allowed us to determine the parameters of the Johnson-Cook damage criteria. Moreover, punching was performed on real parts and compared with simulations to analyze the percentage of burnish surface. The results obtained show that the methodology used was correct and that it can be extrapolated to other types of die-cutting processes by reducing the percentage of surface fractures and predicting the appearance of cracks. Furthermore, it was observed that clearance has a greater influence than processing speed, while the minimum percentage of the burnish area was observed for the minimum values of clearance.
Open Access
A proposal of a constitutive description for aluminium alloys in both cold and hot working
(MDPI, 2016) León Iriarte, Javier; Luis Pérez, Carmelo Javier; Fuertes Bonel, Juan Pablo; Puertas Arbizu, Ignacio; Luri Irigoyen, Rodrigo; Salcedo Pérez, Daniel; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
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.
Open Access
Development of nanostructured AA3103 by equal channel angular pressing and thermal treatments
(Hindawi, 2014) Luis Pérez, Carmelo Javier; Luri Irigoyen, Rodrigo; León Iriarte, Javier; Puertas Arbizu, Ignacio; Salcedo Pérez, Daniel; Pérez Ruiz, Iván; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza; Gobierno de Navarra / Nafarroako Gobernua, Project EUROINNOVA NANOCONS-IIM10784.RI1
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.
Open Access
Experimental and FEM analysis of wear behaviour in AA5083 ultrafine-grained cams
(MDPI, 2020) Luis Pérez, Carmelo Javier; Luri Irigoyen, Rodrigo; Fuertes Bonel, Juan Pablo; León Iriarte, Javier; Salcedo Pérez, Daniel; Puertas Arbizu, Ignacio; Ingeniería; Ingeniaritza
Severe plastic deformation (SPD) processes have attracted a great deal of both scientific and technological interest over the last few years as a consequence of the improvements that are possible to obtain in the microstructure and mechanical properties of the materials manufactured through the use of these kind of processes. However, the practical applications of such materials to obtain mechanical components are significantly fewer. As a direct consequence, the same thing has been observed in the development of studies that show the in-service behaviour of the mechanical components developed in this way. Since one of the industrial objectives of these SPD processes is to obtain functional parts, it is necessary to carry out studies to fill this gap. Therefore, in this study, an analysis of the wear that cams undergo when manufactured from an AA5083 aluminium-magnesium alloy is carried out. The cams were isothermally-forged from materials with and without previous SPD processing by equal channel angular pressing (ECAP). Subsequently, the wear behaviour of these cams was analysed by using specific equipment, which may have been considered to have a block-on-ring configuration, developed for testing in-service wear behaviour of mechanical parts. From this comparative wear study with cams, it is shown that previously-processed materials by ECAP have a better wear performance. Moreover, finite element modelling (FEM) simulations were also included to predict wear in the cams processed in this way. A good agreement between FEM and experimental results was obtained. It is this aspect of performing the wear tests on functional and real mechanical components, and not on laboratory samples, which makes this present research work novel.
Open Access
Manufacturing of nanostructured rings from previously ECAE-processed AA5083 alloy by isothermal forging
(Hindawi, 2013) Luis Pérez, Carmelo Javier; Salcedo Pérez, Daniel; León Iriarte, Javier; Puertas Arbizu, Ignacio; Fuertes Bonel, Juan Pablo; Luri Irigoyen, Rodrigo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
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.
Open Access
Design and optimization of the dies for the isothermal forging of a cam
(Elsevier, 2015) Salcedo Pérez, Daniel; Luis Pérez, Carmelo Javier; Luri Irigoyen, Rodrigo; León Iriarte, Javier; Puertas Arbizu, Ignacio; Fuertes Bonel, Juan Pablo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
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.