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
Analytical modelling of energy density and optimization of the EDM machining parameters of Inconel 600
(MDPI, 2017) Torres Salcedo, Alexia; Puertas Arbizu, Ignacio; Luis Pérez, Carmelo Javier; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
In this present research work, a new modelling of energy density in EDM (Electrical Discharge Machining) is proposed. Energy density can be defined as the amount of energy needed to get a unit volume of material removed, and for its modelling, the whole EDM process has been taken into account. This new definition lets us quantify the energy density that is being absorbed by the workpiece and the electrode. Results are compared to those obtained by die sinking EDM in an Inconel ®600 alloy using Cu-C electrodes. Currently, this material is of great interest for industrial applications in the nuclear, aeronautical and chemical sectors, due to their combinations of good mechanical properties, corrosion resistance and extreme hardness at very high temperatures. The experimental results confirm that the use of negative polarity leads to a higher material removal rate, higher electrode wear and higher surface roughness. Moreover, the optimal condition to obtain a maximum MRR (Material Removal Rate) of 30.49 mm3/min was: 8 A, 100 µs and 0.6, respectively, for the current intensity, pulse time and duty cycle.
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
Experimental analysis of the machinability of 94 WC-6 Co by die-sinking EDM
(MDPI, 2024-12-10) Salvide-González, Unai; Puertas Arbizu, Ignacio; Luis Pérez, Carmelo Javier; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2
Cobalt-bonded tungsten carbide (WC-Co) is widely used in heavy-duty machining applications due to its exceptional hardness and wear resistance, and it is increasingly being adopted in industries such as aerospace and the automotive sector, among others. Its superior mechanical properties make it difficult to machine with conventional methods such as turning or milling. Electrical Discharge Machining (EDM) has emerged as an efficient alternative, as it allows for the machining of hard materials to be carried out without direct contact between the tool and the workpiece, provided that the material has sufficient electrical conductivity. In this study, a multilevel Design of Experiments (DOE) was conducted to analyze the influence of EDM parameters¿specifically, the current intensity and pulse time—on the surface roughness (SR), electrode wear (EW), and material removal rate (MRR) for 94WC—6Co. The results indicate that the current intensity was the most significant factor across all responses, while the pulse time played a secondary role. Surface finishes as low as Ra = 0.47 μm were achieved at I = 2 A and ti = 10 μs.. For each outcome variable, mathematical models were obtained in order to improve the EDM processes and better understand the machining of WC-Co.
Open Access
A study on the EDM drilling of reaction-bonded silicon carbide using different electrode materials
(Springer, 2023) Torres Salcedo, Alexia; Luis Pérez, Carmelo Javier; Puertas Arbizu, Ignacio; Corres Sanz, Jesús María; Ingeniería; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Today, there is a growing demand for efficient hole manufacturing technology in many industries such as aeronautics, automotive and nuclear, among others. Thus, the present study deals with the machining of through holes on SiSiC advanced ceramic by using Electrical Discharge Machining (EDM) drilling technology. Since recommendations related to the electrode characteristics and settings parameters are found to be scant for the industrial use of EDM drilling of SiSiC ceramics, this research work comes to cover this gap as it presents a complete study focused on the influence on different electrodes under rough and finish machining conditions. In particular, the influence of four electrodes materials (copper, copper-tungsten, graphite and copper infiltrated graphite) and three different electrode diameters ranging from 2 to 4 mm are investigated. In addition, the rotational speed of the electrode is also analysed. From the experimental results, both electrode material and machining regime, seem to be the most relevant factors of all. In the case of 2 mm diameter electrode, material removal rate (MRR) with Cu electrode was, approximately, 4.5 times higher than that obtained with a C electrode. In fact, it was found that copper electrode rotating at 20 rpm combined with high values of discharge energy (I = 2 A; ti = 70 µs) is the most economical option in terms of production cost and production time, as it gives a high MRR of 0.4754 mm3/min and a minimum electrode wear (EW) value of 7.52%. Moreover, slightly higher values of MRR were achieved for CuC electrode compared to those obtained with C electrode, indicating that the addition of Cu in the electrode contributes to a greater removal of material. However, a value of Ra of 0.37 µm could be obtained by setting low current intensity values (I = 0.5 A; ti = 45 µs) combined with C electrodes and with no rotation.
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.