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
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
Revisión de las aplicaciones de la electroerosión por penetración al mecanizado de cerámicas conductoras
(CENIM, 2002) Puertas Arbizu, Ignacio; Luis Pérez, Carmelo Javier; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
El término de materiales cerámicos técnicos o materiales cerámicos avanzados se aplica a una gama emergente de materiales, que tienen unas propiedades excelentes de dureza, resistencia al desgaste, resistencia mecánica, resistencia a la corrosión, en un amplio rengo de temperatura. Sin embargo, los materiales con buenas prestaciones suelen ser difíciles de procesar y los materiales cerámicos no son la excepción. Aunque la mayor parte de los materiales cerámicos no son conductores, gracias a la utilización de determinados aditivos metálicos es posible hacer que lo sean y, por lo tanto, éstos pueden ser mecanizados por procesos de electroerosión. El presente trabajo es una revisión de las diferentes aplicaciones de los materiales cerámicos, haciéndose especial hincapié en los materiales cerámicos conductores, así como de los procesos de mecanizado que se pueden emplear en su fabricación, incidiendo fundamentalmente sobre el proceso de la electroerosión por penetración.
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
Using a fuzzy inference system to obtain technological tables for electrical discharge machining processes
(MDPI, 2020) Luis Pérez, Carmelo Javier; Ingeniería; Ingeniaritza
Technological tables are very important in electrical discharge machining to determine optimal operating conditions for process variables, such as material removal rate or electrode wear. Their determination is of great industrial importance and their experimental determination is very important because they allow the most appropriate operating conditions to be selected beforehand. These technological tables are usually employed for electrical discharge machining of steel, but their number is significantly less in the case of other materials. In this present research study, a methodology based on using a fuzzy inference system to obtain these technological tables is shown with the aim of being able to select the most appropriate manufacturing conditions in advance. In addition, a study of the results obtained using a fuzzy inference system for modeling the behavior of electrical discharge machining parameters is shown. These results are compared to those obtained from response surface methodology. Furthermore, it is demonstrated that the fuzzy system can provide a high degree of precision and, therefore, it can be used to determine the influence of these machining parameters on technological variables, such as roughness, electrode wear, or material removal rate, more efficiently than other techniques.
Open Access
Spacing roughness parameters analysis on the EDM of Inconel (R) 600 alloy
(Elsevier, 2017) Torres Salcedo, Alexia; Puertas Arbizu, Ignacio; Luis Pérez, Carmelo Javier; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
Many research studies may be found regarding the measurement of surface roughness parameters. Most of them are focused on amplitude parameters as they are the most commonly used in industry, while little research has been found on the spacing ones. Spacing roughness parameters measure the horizontal characteristics of the surface deviations. In this present study, the influence of current intensity, pulse time and duty cycle on spacing roughness parameters Sm and Pc has been analyzed. Design of experiments techniques are used in order to both model and predict the most influential factors by using a small number of experiments. Current intensity of 2 A, pulse time of 25 mu s and duty cycle of 0.5 are selected as the best machining conditions in order to obtain the lowest surface roughness.
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.
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.