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
EDM machinability and surface roughness analysis of TiB2 using copper electrodes
(Elsevier, 2017-01-05) Torres Salcedo, Alexia; Luis Pérez, Carmelo Javier; Puertas Arbizu, Ignacio; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2
Titanium diboride (TiB2) is a sintered ceramic material which has a high industrial interest due to its excellent mechanical properties, such as immense hardness, elastic modulus, and abrasion resistance. Unlike most ceramics, this material can be machined by using an electrical discharge machining (EDM) process because of its good thermal and electrical conductivity. In this present study the applicability of an EDM process for manufacturing titanium diboride is analysed. To do that, the influence of EDM parameters is studied on three of the most important technological characteristics in EDM: material removal rate (MRR), electrode wear (EW) and surface roughness (Ra). Results confirm that the most influential factor on MRR and Ra is the current intensity whereas in the case of EW, it is the pulse time. Additionally, the control of these parameters allows technological tables to be obtained in order to determine the optimum operating conditions. Such technological tables exist for the case of steels but they do not exist for TiB2, in which the optimal conditions are to be determined experimentally.
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
Filtro de material cerámico electroconductor
(2024) Luis Pérez, Carmelo Javier; Puertas Arbizu, Ignacio; Torres Salcedo, Alexia; Ingeniería; Ingeniaritza
La presente invención se refiere al desarrollo de componentes con cuerpos de materiales cerámicos conductores que presenten orificios pasantes y/o ranuras pasantes para su posterior aplicación como elementos de filtrado, mediante el empleo de procesos de electroerosión por penetración. Entre dichos materiales cerámicos se pueden citar: carburo de silicio infiltrado con silicio (SiSiC), carburo de boro (B{sub,4}C) y diboruro de titanio (TiB{sub,2}), entre otros. Por ello, mediante la presente invención, es posible disponer de componentes para aplicaciones de filtrado con las propiedades inherentes a los materiales cerámicos junto con la gran variedad de formas, precisión dimensional y buen acabado superficial que es posible obtener mediante los procesos de electroerosión. Una de sus aplicaciones de filtrado más destacables sería la fabricación de filtros resistentes a alta temperatura con geometría cilíndrica para el filtrado de líquidos altamente corrosivos e impurezas.
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
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
Surface roughness analysis on the dry turning of an Al-Cu alloy
(Elsevier, 2015) Torres Salcedo, Alexia; Puertas Arbizu, Ignacio; Luis Pérez, Carmelo Javier; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
Nowadays, surface finish has become an important indicator of quality and precision in manufacturing processes and it is considered one of the most important parameter in Industry. In this present study, the influence of different machining parameters on surface roughness has been analyzed. All these parameters have been studied in terms of depth of cut (ap), feed rate (F), cutting speed (Vc) and tool radius (R). A 2030-T4 aluminium alloy has been selected. Moreover, Design of Experiments (DOE) techniques have been used to predict the surface quality in advance and to select the optimal turning conditions. The experimental results revealed that for dry turning operations and for the amplitude parameters, the most significant factor was the interaction effect between the depth of cut and the feed rate. In addition, for facing operations, the feed rate turned out to be the most statistically influential factor of all the surface roughness parameters.
Open Access
EDM machinability and surface roughness analysis of INCONEL 600 using graphite electrodes
(Springer, 2016) Torres Salcedo, Alexia; Puertas Arbizu, Ignacio; Luis Pérez, Carmelo Javier; Ingeniería; Ingeniaritza
Open Access
Análisis de la influencia de las condiciones de proceso sobre el acabado superficial de materiales cerámicos fabricados por electroerosión
(CENIM, 2004) Puertas Arbizu, Ignacio; Luis Pérez, Carmelo Javier; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
El mecanizado por electroerosión (en inglés, Electrical Discharge Machining, EDM) constituye una alternativa emergente frente a otros procesos de fabricación de materiales cerámicos conductores, tales como: mecanizado por láser, mecanizado electroquímico, chorro de agua con abrasivos, mecanizado por ultrasonidos y rectificado con muela de diamante. Debido a su interés en el ámbito industrial, en este trabajo se lleva a cabo un estudio de la influencia de las condiciones de operación sobre el aspecto superficial de tres materiales cerámicos conductores: carburo de boro prensado en caliente (B4C), carburo de silicio infiltrado con silicio (SiSiC) y carburo de wolframio en matriz metálica de cobalto (WC-Co), electroerosionados bajo diferentes condiciones de mecanizado y para el caso particular de regímenes de acabado (Ra ≤ 1 μm).