Open Access
Comparative study of the damage attained with different specimens by FEM
(Elsevier, 2015) Fuertes Bonel, Juan Pablo; Luri Irigoyen, Rodrigo; Luis Pérez, Carmelo Javier; Salcedo Pérez, Daniel; León Iriarte, Javier; Puertas Arbizu, Ignacio; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
This present research work deals with the analysis of the design of different specimen geometries so that by finite volume simulations, the appearance of cracks may be predicted in the case of forging processes. To this end, each of the geometries selected are studied by means of compression tests between plane shape dies in the same conditions (T = 25 ºC). On the one hand, a value for the critical damage value is obtained by applying the Cockroft-Latham’s criterion and on the other hand, a damage distribution along all the specimen volume with the aim of defining a specimen which shows the most likely place for the crack to appear. This crack location may be also determined through visual inspection with the aim of being able to evaluate this experimentally in the near future.
Open Access
Elemento de refrigeración de material cerámico electroconductor
(2024) Luis Pérez, Carmelo Javier; Puertas Arbizu, Ignacio; Torres Salcedo, Alexia; Ingeniería; Ingeniaritza
Elemento de refrigeración de material cerámico electroconductor que comprende un cuerpo (1) con al menos un orificio (2) pasante y/o al menos una ranura (3) pasante, configurados para el paso de un fluido de refrigeración, donde al menos un orificio (2) y/o la al menos una ranura (3) están fabricados mediante electroerosión por penetración sobre el cuerpo (1) de material cerámico electroconductor.
Open Access
Study of the industrial application of diamond-like carbon coatings deposited on advanced tool steels
(MDPI, 2024) Barba Areso, Eneko; Claver Alba, Adrián; Montalá, Francesc; Luis Pérez, Carmelo Javier; Sala, Neus; Colominas, Carles; García Lorente, José Antonio; Ingeniería; Ingeniaritza
The utilization of diamond-like carbon (DLC) coatings has emerged as a promising strategy to enhance the performance, durability, and functionality of industrial tools and components. Recognized for their exceptional attributes such as hardness, wear resistance, low friction, and biocompatibility, DLC coatings have achieved widespread acclaim for their potential to improve the capabilities of tool steels for different applications. This present study shows a comprehensive investigation into the application of DLC coatings on a diverse range of tool steel substrates, encompassing 1.2379, 1.2358, Caldie, K340, HWS, and Vanadis 4. The main aim is to show the effects of DLC coatings on these substrates and to provide an in-depth analysis of their properties during forming processes. Furthermore, this study explores the practical utilization of DLC-coated tool steel components, with a particular focus on their role in cold forming dies. Additionally, the study reviews the application of duplex treatments involving plasma nitriding to enhance DLC coating performance. To sum up, this study pursues a threefold objective: to investigate DLC coatings’ performance on diverse tool steel substrates; to assess the potential for improvement through nitriding; and to evaluate the behavior of DLC coatings in the cold stamping of S235 steel, which is of great technological and industrial interest to the cold forging sector.
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
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
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
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
Optimal machining strategy selection in ball-end milling of hardened steels for injection molds
(MDPI, 2019) Buj Corral, Irene; Ortiz Marzo, José 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
Modeling of surface roughness in honing processes by using fuzzy artificial neural networks
(MDPI, 2023) Buj Corral, Irene; Sender, Piotr; Luis Pérez, Carmelo Javier; Ingeniería; Ingeniaritza
Honing processes are abrasive machining processes which are commonly employed to improve the surface of manufactured parts such as hydraulic or combustion engine cylinders. These processes can be employed to obtain a cross-hatched pattern on the internal surfaces of cylinders. In this present study, fuzzy artificial neural networks are employed for modeling surface roughness parameters obtained in finishing honing operations. As a general trend, main factors influencing roughness parameters are grain size and pressure. Mean spacing between profile peaks at the mean line parameter, on the contrary, depends mainly on tangential and linear velocity. Grain Size of 30 and pressure of 600 N/cm2 lead to the highest values of core roughness (Rk) and reduced valley depth (Rvk), which were 1.741 µm and 0.884 µm, respectively. On the other hand, the maximum peak-to-valley roughness parameter (Rz) so obtained was 4.44 µm, which is close to the maximum value of 4.47 µm. On the other hand, values of the grain size equal to 14 and density equal to 20, along with pressure 600 N/cm2 and both tangential and linear speed of 20 m/min and 40 m/min, respectively, lead to the minimum values of core roughness, reduced peak height (Rpk), reduced valley depth and maximum peak-to-valley height of the profile within a sampling length, which were, respectively, 0.141 µm, 0.065 µm, 0.142 µm, and 0.584 µm.