Open Access
Experimental modelling of critical damage obtained in Al-Mg and Al-Mn alloys for both annealed state and previously deformed by ECAP
(Elsevier, 2016) Luri Irigoyen, Rodrigo; Fuertes Bonel, Juan Pablo; Luis Pérez, Carmelo Javier; Salcedo Pérez, Daniel; Puertas Arbizu, Ignacio; León Iriarte, Javier; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
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.
Open Access
Análisis de la influencia del tratamiento térmico de envejecimiento en la modificación de las propiedades mecánicas de la aleación AA6060 procesada por ECAE
(CENIM, 2011) Pérez Ruiz, Iván; Luis Pérez, Carmelo Javier; Luri Irigoyen, Rodrigo; León Iriarte, Javier; Puertas Arbizu, Ignacio; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
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.
Open Access
Analysis of fatigue and wear behaviour in ultrafine grained connecting rods
(MDPI, 2017) Luri Irigoyen, Rodrigo; Luis Pérez, Carmelo Javier; León Iriarte, Javier; Fuertes Bonel, Juan Pablo; Salcedo Pérez, Daniel; Puertas Arbizu, Ignacio; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
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.
Open Access
Design and experimentation of a hydrokinetic turbine for electricity generation in closed pipes
(World Scientific and Engineering Academy and Society, 2024) Armañanzas Goñi, Javier; Alcalá, Marina; Fuertes Bonel, Juan Pablo; León Iriarte, Javier; Torres Salcedo, Alexia; Gil Liberal, Miguel; Ingeniería; Ingeniaritza
In the present research work, a device for electrical energy generation to be used in water pipelines has been designed, simulated, and tested. To achieve this, a study of the most influential parameters involved in the experiment has been carried out and both, the turbine model and the geometry of the experimental test pipe, have been selected through CFD simulations. Next, the Design of Experiments (DOE) has been used to obtain the configuration with a higher energy extraction from running water. Finally, the turbine and the test pipe section have been manufactured by 3D printing and the experimental tests have been carried out with the optimal configuration to validate the results obtained in the CFD simulations. To simulate the exchange of energy between the water and the turbine, the CFD software SIMULIA XFlow has been used.
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
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.
Open Access
Design and mechanical properties analysis of AA5083 ultrafine grained cams
(MDPI, 2017) Salcedo Pérez, Daniel; Luis Pérez, Carmelo Javier; Luri Irigoyen, Rodrigo; Puertas Arbizu, Ignacio; León Iriarte, Javier; Fuertes Bonel, Juan Pablo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
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.
Open Access
Design, optimization, and mechanical property analysis of a submicrometric aluminium alloy connecting rod
(Hindawi, 2015) Fuertes Bonel, Juan Pablo; León Iriarte, Javier; Luis Pérez, Carmelo Javier; Salcedo Pérez, Daniel; Puertas Arbizu, Ignacio; Luri Irigoyen, Rodrigo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
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.
Open Access
Mechanical properties analysis of an Al-Mg alloy connecting rod with submicrometric structure
(MDPI, 2015) León Iriarte, Javier; Salcedo Pérez, Daniel; Murillo Crespo, Óscar; Luis Pérez, Carmelo Javier; Fuertes Bonel, Juan Pablo; Puertas Arbizu, Ignacio; Luri Irigoyen, Rodrigo; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
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.
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.