Brass Electrodes Research Articles

Experimental studies on aluminum powder mixed electro discharge machining of ultra-light weight Mg-6Al alloy

Innovation of new energy efficient lightweight material is a new trend for researchers to fulfill the industry demand. Lightweight materials are becoming more popular in the automobile, aerospace and health sector. In this verse, magnesium alloys found more suitable owing to its strength to weight ratio approach, damping capacity and stiffness property. Tougher materials have less machinability index. Hence, to machine magnesium alloy by conventional process is little bit difficult, because of its high stiffness. In present work attempt has been made to machine Mg-6Al alloy by PMEDM process in order to reveal its machining characteristics and to define best-input parameters based on its output responses. In this context aluminum, powder with concentration 0.5gm/ltr is mixed with kerosene dielectric and brass, copper, stainless steel and bright mild steel electrodes are used for experimentation. Machining efficiencies of each electrode in terms of MRR, TWR, SR and RoC are evaluated. The results show that maximum MRR is achieved by brass electrode followed by copper, bright M.S and stainless steel. Almost fourteen times higher MRR is achieved in case of the brass electrode than bright M.S electrode. However, stainless steel electrode offers lowest TWR, SR and RoC.

Investigation and wear analysis of Al-SiC<SUB align="right">p nano composites and study of its machinability using electro discharge machining

The present research work has been given the importance on proper distribution of silicon carbide nano particles with different volume fractions of 1%, 1.5% and 2% in the aluminium metal matrix. The paper also deals with the wear analysis of the developed Al-SiCp nano composite by using dry sliding wear test with pin on disc machine. XRD analysis of the Al-SiCp nano composite work material has been performed to determine the purity and grain size of the sample. The present work also focuses on metal matrix nano composites during electric discharge machining (EDM) process using brass, aluminium and copper as tool electrodes. Electrode wear ratio (EWR) of the tool as well as material removal rate (MRR) of the workpiece has been determined and it was found that copper is the best and preferable electrode followed by aluminium and brass electrodes due to its higher MRR and lower EWR.

Трансмутация части экстрагированного материала латунных электродов при импульсах электрического тока в водном растворе NaCl

Трансмутация части экстрагированного материала латунных электродов при импульсах электрического тока в водном растворе NaCl

Analysis, predictive modelling and multi-response optimization in electrical discharge machining of Al-22%SiC metal matrix composite for minimization of surface roughness and hole overcut

Due to the widespread engineering applications of metal matrix composites especially in automotive, aerospace, military, and electricity industries; the achievement of desired shape and contour of the machined end product with intricate geometry and dimensions that are very challenging task. This experimental investigation deals with electrical discharge machining of newly engineered metal matrix composite of aluminum reinforced with 22 wt.% of silicon carbide particles (Al-22%SiC MMC) using a brass electrode to analyze the machined part quality concerning surface roughness and overcut. Forty-six sets of experimental trials are conducted by considering five machining parameters (discharge current, gap voltage, pulse-on-time, pulse-off-time and flushing pressure) based on Box-Behnken's design of experiments (BBDOEs). This article demonstrates the methodology for predictive modeling and multi-response optimization of machining accuracy and surface quality to enhance the hole quality in Al-SiC based MMC, employing response surface methodology (RSM) and desirability function approach (DFA). Finally, a novel approach has been proposed for economic analysis which estimated the total machining cost per part of rupees 211.08 during EDM of Al-SiC MMC under optimum machining conditions. Thereafter, under the influence of discharge current several observations are performed on machined surface morphology and hole characteristics by scanning electron microscope to establish the process. The result shows that discharge current has the significant contribution (38.16% for Ra, 37.12% in case of OC) in degradation of surface finish as well as the dimensional deviation of hole diameter, especially overcut. The machining data generated for the Al-SiC MMC will be useful for the industry.

Investigation and wear analysis of Al-SiC<SUB align="right">p nano composites and study of its machinability using electro discharge machining

The present research work has been given the importance on proper distribution of silicon carbide nano particles with different volume fractions of 1%, 1.5% and 2% in the aluminium metal matrix. The paper also deals with the wear analysis of the developed Al-SiCp nano composite by using dry sliding wear test with pin on disc machine. XRD analysis of the Al-SiCp nano composite work material has been performed to determine the purity and grain size of the sample. The present work also focuses on metal matrix nano composites during electric discharge machining (EDM) process using brass, aluminium and copper as tool electrodes. Electrode wear ratio (EWR) of the tool as well as material removal rate (MRR) of the workpiece has been determined and it was found that copper is the best and preferable electrode followed by aluminium and brass electrodes due to its higher MRR and lower EWR.

Electrical Discharge Drilling of micro-hole on Inconel 718 using Rotary Tubular Electrode

Abstract Micro drilling process plays a vital role in modern high end applications in the field of aerospace, nuclear and micro mould making industries. Conventional micro drilling poses challenges not only type of tools but also its precise rotation for an improved hole geometry. Micro EDM process is capable of meeting current industrial requirements. In this paper, an attempt is made to investigate the influence of the characteristics of Inconel 718 on electric discharge drilling process for 0.5 mm diameter micro hole with tubular brass electrode of same size. Experiments were conducted using demineralized water as dielectric medium by varying current, pulse-on time and pulse-off time in three levels while keeping electrode diameter, spindle speed, feed rate and material thickness constant. Taguchi analysis was performed on L9 orthogonal array experimental results show that the effects of input parameters are having varying contributions on output parameters material removal rate, hole taper and its change in hole size called diameter over cut during process

Modelling and optimization of different quality characteristics in electric discharge drilling of titanium alloy sheet

Abstract The present research work is concentrated around the machining of titanium grade 5 alloy using electric discharge drilling. The process response parameters viz. hole taper and hole dilation have been calculated by performing experiments. During the experiments titanium grade 5 alloy has been taken as a workpiece with brass electrode as a tool. The experimentally calculated process parameters have been optimized using grey relational analysis. The main objective of this research is to maximize the hole circularity along with minimum hole taper and dilation by selecting the optimal input parameters. From the results it has been found that discharge current is the most effective parameter for the given conditions.

Ultrafast drilling of Inconel 718 using hybrid EDM with different electrode materials

In recent years, the popularity of nickel-based super alloys has been on the rise due to their widespread application in oil and gas, aerospace and automobile, marine and biomedical industries. The unique combination of superior mechanical and chemical properties like hardness, strength, temperature and corrosion resistance is responsible for the extensive application of these alloys. However, these properties pose challenges during the conventional machining of nickel-based super alloys. The low thermal conductivity and high work-hardening characteristics of Inconel 718 make it difficult to machine. To overcome the aforementioned problem, a hybrid non-contact electrical discharge and arc-machining process has been employed. In this process, an additional DC power supply is employed in conjunction with the normal EDM-pulsed power supply. Furthermore, the selection of proper electrode material plays an important role in defining the machining performance. In this study, in order to select a suitable electrode material for the newly developed process, several experimental investigations have been conducted with three different electrode materials, namely brass, copper (Cu) and copper tungsten (CuW). The results have shown that, for all the current settings, brass electrode provides the highest material removal rate (MRR), followed by Cu and CuW electrodes. However, CuW exhibited the lowest electrode wear rate (EWR). Moreover, the average surface roughness and surface characteristics of the electrodes after machining were investigated as well. Based on all the performance parameters, CuW appears to be the best choice for the hybrid process to machine Inconel 718.

Corrosion inhibiting performance and mechanism of protic ionic liquids as green brass inhibitors in nitric acid

Four protic ionic liquids (ILs) were synthesized via a one-step method by using benzotriazole (BTA) and benzimidazole as cations, and benzenesulfonic acid and 2-naphthalenesulfonic acid (NSA) as anions. These ILs were used as green corrosion inhibitors for brass specimens in a nitric acid solution. The structure of the protic ILs was characterized by 1H-NMR, 13C-NMR, and FT-IR spectroscopy. The effects of the IL structure, IL concentration, acid concentration, and corrosion time on the surface morphology of brass specimens and the inhibition efficiency (η%) of ILs were investigated by the weight loss method combined with SEM and EDS spectroscopy. Polarization curves and impedance spectroscopy were used to analyze the electrochemical corrosion inhibition mechanism of ILs. Results showed that IL synthesis was a proton transfer process, and the proton of the –SO3H group on NSA was deprived by BTA. IL [BTA][NSA], which had a high charge density and large conjugate π band, was the most effective inhibitor for brass corrosion. The η% of [BTA][NSA] decreased with the increase in acid concentration and corrosion time, which showed an increment with the increase in [BTA][NSA] concentration. The higher the η% of [BTA][NSA] is, the smoother the surface of the brass specimens is, and the smaller the undistributed area of Cu element will be. Corrosion inhibiting mechanism from electrochemical analysis indicated that the addition of [BTA][NSA] increased the polarization resistance of the brass electrode significantly and suppressed both anodic and cathodic reactions.

A sustainability index for the micro-EDM drilling process

The increasing attention being paid to environmental protection has resulted in significant changes in all production systems. Moreover, system efficiency and productivity should be improved and manufacturing system design must take ecological constraints into consideration. Accordingly, the definition of an index of sustainability can help in assessing the different and sometimes conflicting aspects of a manufacturing process, such as manufacturing costs, energy consumption, waste management, personnel health, and operational safety. In this study, a sustainability index is defined and applied to a micro-electrical discharge machining (EDM) process in drilling operations. The index is composed of five sub-indices that evaluate a particular aspect: energy consumption, environmental impact, dielectric consumption, wear of electrode, and machining performance in general. Each sub-index is calculated by assigning an economic cost to the undesirable impact through a formulae of coefficients (weights) and variables (such as machining time and electrode wear). High index values mean that the process consumes a significant amount of resources and/or produces environmental pollution that is poorly sustainable. In contrast, lower values indicate that the process consumes fewer resources; therefore, it has a lower impact and is more sustainable. The developed sustainability index is applied to an experimental case: the drilling of micro holes in stainless steel (AISI 316L) and titanium alloy (Ti6Al4V) using two types of electrodes (brass and tungsten carbide). Several types of conventional and innovative dielectrics are used (both liquid and gas): kerosene, demineralised water, vegetable oil, compressed air, and oxygen gas. For each combination of workpiece, electrode material, and dielectric tested, the sustainability index is calculated and the outcomes are analysed. It is found that the dielectric plays a major role in the EDM process, because it significantly influences the machining performance. Moreover, it affects the environment in terms of the quantity of consumed resources and pollution created by the process. The type of electrode also affects the process. Within the limit of the present investigation, water and vegetable oil have the lowest environmental impact. For these dielectrics, brass electrodes halve the impact when stainless steel is processed, while tungsten carbide is better for titanium sheets. The use of kerosene as a dielectric coupled with tungsten carbide as an electrode makes the process less green and should be avoided. The combination of air as a dielectric and tungsten carbide as an electrode proves interesting. Oxygen as a dielectric shows instabilities during the process, thus performing poorly in terms of the index. The proposed model for measuring the sustainability of the micro-EDM drilling process is designed to be useful in industrial applications and is easily computable. The index provides a tool that can assist in the decision-making stage of selecting conditions aimed at minimising environmental impact.

Investigation on EDM machining of Ti6Al4V with negative polarity brass electrode

ABSTRACTThis research paper focus on the machinability studies of Ti6Al4V material during electrical discharge machining (EDM) process. Discharge time, current, and discharge voltage are taken as input process variables. Experiments are conducted on Ti6Al4V material to explore the effect of these input variables on material removal rate (MRR), surface roughness, thickness of white layer and microcracks taken as output variables. The machined components are analyzed using three-dimensional surface topography and scanning electron microscope micrographs. It is found, by increasing discharge time and current, MRR and thickness of white layer is increased whereas surface finish gets worsened. Microcracks, blow holes, and redeposition of workpiece as debris are perceived on machined workpiece. A modified equation is proposed to estimate diameter of crater taking into account the discharge energy and latent heat of vaporization of workpiece material. Compared with experimental data, the proposed equation predicts diameter of crater an error of 16.89%.

Evaluation of the sustainability of the micro-electrical discharge milling process

The sustainability evaluation of an industrial process is an actual issue: a process should not only grant part quality and high production rates at the lowest cost, but it should minimize its impact on the environment as well. Micro‐EDM (Electrical Discharge Machining) is widely used in micro machining for its small force and high precision and environmental aspects related this technology are taken into account. In this paper, an evaluation of the micro‐ED milling process concerning the sustainability manufacturing was made. For this purpose, a method to assess the sustainability process was developed, taking into account the energetic consumption, the environmental impact, the dielectric consumption, the wear of the electrode and the machining performance. This method was applied for the execution of micro‐pockets using two workpiece materials, two types of electrode and five types of dielectric, both liquid and gaseous. This analysis permits the identification of the critical aspects of the micro‐ED milling process form the point of view of the sustainability. The comparison between the different solutions in terms of electrode material and dielectric underlines interesting considerations about the usage of non‐traditional dielectrics. As regards electrode material, the environmental impact process when brass electrode is adopted is lower than tungsten carbide electrode. As concerns dielectric, water reveals to be the most sustainable dielectric; vegetable oil and oxygen, proved to be valid substitutes to traditional dielectrics under several viewpoints, including sustainability.

Research into EDM of Beryllium Foil

This paper concerns with a machining experiment on the beryllium sample by electrical discharge machining (EDM), and the experiment proves the machinability in beryllium foil machining of EDM. A brass electrode was chosen for the machining, and the relationship between the tool wear and the process condition was revealed. By the alternation of the positive polarity machining and the negative polarity machining, the tool wear caused by electric erosion was furthest controlled. The foil with a thickness of (0.05~0.06) mm was achieved, and the Ra of (0.18~0.20) μm and the P-V value of 0.78 μm were measured through white-light interference.

Corrosion of α-Brass in Solutions Containing Chloride Ions and 3-Mercaptoalkyl-5-amino-1H-1,2,4-triazoles

The protective effect of 3-mercaptoalkyl derivatives of 5-amino-1H-1,2,4-triazole against corrosion of α-brass in a chloride media was studied using polarization curves, electrochemical impedance spectroscopy, and full-scale corrosion testing. The brass electrode remains passive up to the activation potential, which is much higher than in solutions without organic additives, and it increases with the concentration of the inhibitor. The protection degree of all the studied inhibitors reaches its maximum of over 99% in solutions with the concentration of the inhibitor Cinh ≥ 0.10 mM. The protective effect increases with the length of the alkyl chain. All the studied derivatives are effective against atmospheric corrosion of α-brass. A protective film is formed on the brass surface, and it most probably includes oxides as well as complex compounds of zinc and copper with the molecules of the inhibitors. The impedance spectroscopy demonstrated that the presence of the inhibitor results in a decrease in the double-layer capacitance and an increase in the polarization resistance, which proves that the protective film actually forms on the brass surface. The quantum chemical analysis of the optimized molecular structures demonstrates that all the studied inhibitors should have a similar protective effect, which agrees with the experimental results.

Influence of process parameters in electrical discharge machining on H13 die steel

H13 die steel is characterized by its high hardness and need for special surface features that are obtained by nontraditional machining processes. Electrical discharge machining (EDM) is used to machine hard materials and to produce complicated shapes. In this work, different EDM process parameters are investigated on H13 die steel. Several experiments are conducted to study the effect of three process parameters: peak current (Ip), pulse on-time (Ton) and electrode material on the machining process of H13 die steel. The machining process is evaluated by material removal rate (MRR), electrode wear ratio (EWR%) and surface roughness (SR) as indicators of the process efficiency in terms of quality and cost. Taguchi method was used to investigate the significant effect of process parameters on the performance measurements and the optimal parameters of the EDM process. For analysis and explanations Minitab version 17 software was used. Different process parameters were experimentally investigated and statistically analyzed and the results showed that the copper electrode leads to the highest MRR and lowest EWR%; whereas the brass electrode leads to the lowest SR.

The Effectiveness of Some Organic Polymers As Corrosion Inhibitors for Carbon Steel and Brass in Acidic Media

Three organic polymers were studied as corrosion inhibitors for carbon steel type OLC 45 and brass in 1M H2SO4 and 1M HCl solution using potentiostatic and potentiodynamic polarization methods, electrochemical impedance spectroscopy (EIS), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and metallurgical microscopy techniques. The polymers involved in the study are three sodium polyacrylates hydrophobically modified with linear and cyclo-dodecyl and respectively, dihexyl chain. We suppose that, these polymers inhibit corrosion of metal electrodes by a protective mechanism can be owed to either the adsorption of inhibitor molecules forming a protective film or obtaining a insoluble compound and repairing the porous oxide layers. Experimental data showed that these polymers achieved a significant inhibiting action on brass and carbon steel corrosion and act that a mixed corrosion inhibitors and it could be proved by the effects of polymers on the electrochemical properties of metal electrodes. The adsorption of the polymers on the electrodes surface obeys to the Langmuir isotherm model. The temperature influence on the corrosion behaviour of the metal electrodes in 1M H2SO4 and 1M HCl with and without the inhibitor at 500 ppm was analyzed in the temperature domain from 293 to 313 K. The negative value of thermodynamic parameter like Gibbs free energy of adsorption shows the spontaneity of adsorption process. The experimental results indicated that the corrosion rate have been meaningfully reduced in inhibited solutions when in comparison with the corrosive medium and to increase of the protection effect. Moreover, characterization utilizing FT-IR confirms the adsorption of inhibitors and the constitution of corrosion products on the working electrode surface. EIS and potentiodynamic polarization results demonstrate its corrosion protection capacity. The examined polymers exhibited very good inhibition properties for OLC 45 and brass electrode in 1M H2SO4 and 1M HCl medium while the corrosion current density decreased and the inhibitor efficiency increased with increasing inhibitors concentrations.

Improving of geometric precision in the manufacture of circular holes using technology WEDM

WEDM technology is among the final technology. It is characterized by the high quality of the machined surface. Therefore, a small geometric deviation from the desired shape, position, orientation or run out may have a significant impact on the functionality of the finished component. Its range is largely influenced by the accuracy of the applied electroerosion device, the precision of the workpiece and tool setting, the machining method, but also the combination of each other and the adjustment of all process parameters. They result in the final quality of the machined surface not only in terms of roughness parameters but also in terms of geometric precision of the machined surface. The aim of the paper was to describe the possibilities of improving the geometrical accuracy of WEDM with thin brass electrodes. At the same time, it contributes to an existing database of knowledge that defines the influence of selected aspects on the geometrical accuracy of the machined area in the production of circular openings.

Optimizing Machining Process of E31 Steel for Improved Surface Roughness

End milling (EM) and electric discharge machining (EDM) are frequently used for machining high chromium steel. The superior surface finish is among the key requirements for the improved functional behavior, wear resistance, and fatigue life high chromium steel components. The present work includes optimization of EM (using Taguchi method) and EDM processes (by selecting appropriate electrode) for machining of the high chromium steel keeping high material removal rate (MRR) and superior surface finish as the objectives. Additionally, the effect of coolant on surface roughness was evaluated. For EM, the feed rate was found the most influential parameter and the high spindle speed, small feed rate result-in better surface finish whereas the depth of cut has the insignificant effect on the surface roughness for the selected rages of process parameters. The scanning electron microscope (SEM) micrographs revealed that flood cooling decreases the surface defects and mostly high chromium steel samples were having a lower surface roughness when coolant was used. For EDM, the brass electrode results in a superior surface finish but a lesser MRR than the copper electrode while machining high chromium steel.

Comparison of machining characteristics of Inconel 601 with Brass and Graphite electrode in EDM using Response Surface Methodology (RSM)

Nickel-based super alloy (such as Inconel) is widely used in aerospace, nuclear, and chemical industries because of its excellent mechanical and chemical properties at elevated temperatures. Inconel comes under the category of “diffcult-to-cut” materials. In the present case, an experimental investigation on assessing machining performance during EDM of Inconel 601 has been delineated herein. Attempt has been made on evaluating optimal machining parameters setting to achieve satisfactory machining yield. A Box–Behnken design of response surface methodology has been adopted to es timate the effect of machining para meters on the response. Experiments have been carried out by varying gap voltage, peak current, pulse-on time (each varied at three discrete levels) to examine the extent of machining performance in terms of material removal rate using Brass and Graphite electrode.

Towards the Prediction of Micro-EDM Drilling Performance on WC Varying the Hole Depth

The present work deals with the execution of through micro-holes on tungsten carbide plates using a micro-EDM (Electrical Discharge Machining) machine. The investigation focuses on the monitoring of the performance during the drilling phase in order to obtain the in progress behavior of the performance indexes. The experiments were carried out by varying some process parameters such as peak current, voltage and frequency to achieve both high and low power discharge conditions. Regarding electrodes, the most commonly industrial used ones were selected: tubular tungsten carbide and brass. The performance indexes taken into account were machining time, Material Removal Rate (MRR), Tool Wear (TW) and Tool Wear Ratio (TWR). Brass electrode always resulted to be the best solution in terms of drilling speed even though the wear of this electrode type is remarkable higher than the tungsten one. The evolution of the performance indexes during the drilling operation showed the same trend for both electrodes: increasing the hole depth, the drilling operation proceeds in a more difficult way, due to the evacuation of debris that becomes more difficult and therefore the performance indexes get worse. Finally, the technology windows of the cumulated MRR and TWR were defined for both electrode materials, in order to predict the micro EDM process performance varying the hole depth.