Open Access
Spacing roughness parameters analysis on the EDM of TiB2
(Elsevier, 2017) Torres Salcedo, Alexia; Luis Pérez, Carmelo Javier; Puertas Arbizu, Ignacio; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza
Titanium diboride (TiB2) is a novel sintered ceramic material which has attracted a great deal of interest because of its excellent mechanical properties, wear resistance and chemical resistance. At present, this ceramic is used in specialized applications in such areas as impact resistant armor, cutting tools, crucibles and wear resistant coatings. In this present research work, effects of current intensity, pulse time and duty cycle on the spacing roughness parameters Sm and Pc have been studied. In addition, statistical tools based on the design of experiments as well as multiple linear regression techniques have been used. Experimental results suggest that the optimal conditions to obtain a minimum Sm of 52.60 gm and a maximum Pc of 190.60 cm(-1) were: 2 A, 5 mu s and 0.4, respectively, for current intensity, pulse time and duty cycle.
Open Access
Multi-objective optimization of electrical discharge machining parameters using particle swarm optimization
(Elsevier, 2024-01-22) Luis Pérez, Carmelo Javier; Ingeniería; Ingeniaritza; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
This manuscript presents an efficient multi-objective optimization method based on using particle swarm optimization together with a desirability function that can be applied where the response variables may have an opposite behavior and where the range of variation of the independent variables as well as those of the responses are subjected to constraints, which has a great deal of industrial interest. For example, maintaining roughness and dimensional tolerances within a tolerance range is determined by the design requirements of the manufactured parts (shape errors, microgeometry errors, etc.) and these requirements must be met in the manufacture of parts. It is demonstrated that it is possible to obtain optimal results in the ranges of variation considered for the independent variables, with regard to those obtained by experimentation. Similarly, models based on Adaptive Network-based Fuzzy Inference Systems are used to solve the problem that may arise from the inadequate fitting of the regression models. Thus, thanks to this present study a fast and efficient method is available for the multiple-optimization of response variables, subject to constraints on both response and independent variables, which are obtained from experiments and modelled by means of soft computing techniques. Furthermore, it is also demonstrated that it is possible to obtain technology tables for various manufacturing processes, which is of great interest from a technological point of view so as to obtain the most suitable processing conditions.
Open Access
Multi-objective optimization of tool wear, surface roughness, and material removal rate in finishing honing processes using adaptive neural fuzzy inference systems
(Elsevier, 2023) Buj Corral, Irene; Sender, Piotr; Luis Pérez, Carmelo Javier; Ingeniería; Ingeniaritza
Honing processes are usually employed to manufacture combustion engine cylinders and hydraulic cylinders. Honing provides a crosshatch pattern that favors the oil flow. In this paper, Adaptive Neural Fuzzy Inference System (ANFIS) models were obtained for tool wear, average roughness Ra, cylindricity and material removal rate in finishing honing processes. In addition, multi-objective optimization with the desirability function method was applied, in order to determine the process parameters that allow minimizing roughness, cylindricity error and tool wear, while maximizing material removal rate. The results showed that grain size and tangential velocity should be at their minimum levels, while density, pressure and linear velocity should be at their maximum levels. If only roughness, cylindricity error and tool wear are considered, then low grain size, low pressure and low linear velocity are recommended, while density and tangential velocity vary, depending on the optimization algorithm employed. This work will help to select appropriate process parameters in finishing honing processes, when roughness, cylindricity error and tool wear are to be minimized.
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
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
On the application of a design of experiments along with an anfis and a desirability function to model response variables
(MDPI, 2021) Luis Pérez, Carmelo Javier; Ingeniería; Ingeniaritza
In manufacturing engineering, it is common to use both symmetrical and asymmetrical factorial designs along with regression techniques to model technological response variables, since the in-advance prediction of their behavior is of great importance to determine the levels of variation that lead to optimal response values to be obtained. For this purpose, regression techniques based on the response surface method combined with a desirability function for multi-objective optimization are commonly employed, since it is usual to find manufacturing processes that require simultaneous optimization of several variables, which exhibit in many cases an opposite behavior. However, these regression models are sometimes not accurate enough to predict the behavior of these response variables, especially when they have significant non-linearities. To deal with this drawback, soft computing techniques are very effective in overcoming the limitations of conventional regression models. This present study is focused on the employment of a symmetrical design of experiments along with a new desirability function, which is proposed in this study, and with soft computing techniques based on fuzzy logic. It will be shown that more accurate results than those obtained from regression techniques are obtained. Moreover, this new desirability function is analyzed in this study.
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
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.