Person:
Luis Pérez, Carmelo Javier

person.page.identifierURI

https://academica-e.unavarra.es/handle/2454/49469

Last Name

Luis Pérez

First Name

Carmelo Javier

person.page.departamento

Ingeniería

person.page.instituteName

INAMAT2 - Institute for Advanced Materials and Mathematics

ORCID

0000-0002-1363-1667

person.page.upna

2277

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Now showing 1 - 10 of 42

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
Development of a machining strategy to manufacture SiSiC nuts by EDM
(SAGE Publications, 2024) Torres Salcedo, Alexia; Puertas Arbizu, Ignacio; Luis Pérez, Carmelo Javier; Ingeniería; Ingeniaritza
Today, the high-precision manufacturing of small cavities in difficult-to-machine materials is still a challenge, even more so if they need to be threaded. The machining time, the wear suffered by the electrodes and the surface finish are determining factors in the efficiency of the threading process. However, there is scant literature on this subject so there is a need to study the process and the parameters involved. Thus, this study presents a novel machining strategy for the manufacture of nuts using die-sinking electrical discharge machining (EDM). Moreover, the novelty of this strategy is that it is carried out in a single stage and with a conventional EDM generator. To do so, a design of experiments (DOE) methodology has been followed. First, the optimal machining conditions are determined by studying the influence of EDM parameters on operation variables and mathematical models are developed using multiple linear regression. These models allow the behavior of the response variables under study to be predicted. Finally, this machining strategy developed from the previous experimental results is validated in the manufacturing process of a final part, specifically a square nut. It can be concluded that the mathematical model is good enough to predict the experimental results. Thus, the new method presented and described in this present study allowed a nut to be obtained with a real arithmetic mean deviation of the roughness profile (Ra) value of 1.27 μm whereas the predicted value from the model was 1.28 μm. To do so, the machining conditions selected were: 4 A (current intensity), 5 µs (pulse time) and 0.4 (duty cycle), which also gave a material removal rate (MRR) value of 0.5370 mm3/min. The machining strategy proposed here may be used for future research works related to the manufacturing of mechanical joints made of conductive ceramic materials.
Open Access
Simulación y procesado de aleaciones de aluminio mediante estirado en canal angular constante (ECAD)
(CENIM, 2002) Luis Pérez, Carmelo Javier; Garcés Inuñez, Y.; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
En este trabajo se estudia el proceso denominado ECAD (Equal Channel Angular Drawing) que consiste en hacer atravesar un material a través de una matriz de sección transversal constante, que presenta un ángulo comprendido, generalmente, entre 90º y 135º. Para ello, se han procesado tres aleaciones de aluminio: 1370, 6101 y la aleación 6061 mediante las rutas A, B y C. En ellas se observa la evolución de la microestructura según el número de pasadas realizadas (N) y según el tratamiento térmico. Además, la microscopía óptica y SEM muestran la reducción en el tamaño de grano de las aleaciones procesadas respecto a la aleación de partida. Asimismo, se realiza simulación del proceso por elementos finitos, con ángulos de 90º y de 120º, en condiciones de baja fricción (µ = 0,01) y de alta fricción (µ = 0,4) para determinar las condiciones de fricción conducentes a valores mayores de deformación y a una mayor homogeneidad. Los resultados obtenidos al procesar la aleación 1370 indican que es posible conseguir tamaños de grano de 7 µm con la primera pasada de ECAD, mediante la Ruta C. Ello indica que el procesado de aleaciones mediante ECAD puede obtener aplicabilidad industrial si durante el mismo se realiza una pasada final a través de una hilera de calibrado con la finalidad de obtener una sección transversal constante en las aleaciones procesadas.
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
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
Optimal machining strategy selection in ball-end milling of hardened steels for injection molds
(MDPI, 2019) Buj Corral, Irene; Ortiz Marzo, Jose Antonio; Costa Herrero, Lluís; Vivancos Calvet, Joan; Luis Pérez, Carmelo Javier; Ingeniería; Ingeniaritza
In the present study, the groups of cutting conditions that minimize surface roughness and its variability are determined, in ball-end milling operations. Design of experiments is used to define experimental tests performed. Semi-cylindrical specimens are employed in order to study surfaces with different slopes. Roughness was measured at different slopes, corresponding to inclination angles of 15 degrees, 45 degrees, 75 degrees, 90 degrees, 105 degrees, 135 degrees and 165 degrees for both climb and conventional milling. By means of regression analysis, second order models are obtained for average roughness Ra and total height of profile Rt for both climb and conventional milling. Considered variables were axial depth of cut a(p), radial depth of cut a(e), feed per tooth f(z,) cutting speed v(c,) and inclination angle Ang. The parameter a(e) was the most significant parameter for both Ra and Rt in regression models. Artificial neural networks (ANN) are used to obtain models for both Ra and Rt as a function of the same variables. ANN models provided high correlation values. Finally, the optimal machining strategy is selected from the experimental results of both average and standard deviation of roughness. As a general trend, climb milling is recommended in descendant trajectories and conventional milling is recommended in ascendant trajectories. This study will allow the selection of appropriate cutting conditions and machining strategies in the ball-end milling process.
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
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
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).
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.