Characteristics of Ternary Metal (Cu-Ni-TiN) Electrodes Used in an Electrical Discharge Machining Process

In the industrial field, electric discharge machining (EDM) is the most commonly used non-traditional machining process because it has the potential to machine electrically conductive materials of high hardness. To satisfy the need for rapid and economical fabrication of EDM electrodes, techniques that use the addition of more metal in the manufacturing process are gaining in popularity. This study presents an investigation of the characterization of ternary metals (Cu–Ni–TiN) for EDM electrodes by using powder metallurgy, which leads to enhancement of the mechanical properties, such as the hardness, electrical properties, and other properties, for the formation of Cu in Ni-TiN electrodes using a cold press at pressures of 18, 20, and 22 MPa. The influences of the parameters of this process were identified for the betterment of Cu–Ni–TiN on the surface. The specimens were calcined in a furnace at 1100 °C for 1 h, with a mixture of argon and hydrogen gas as a controlled gas in the ratio of 95:5. The specimens were investigated in terms of hardness, electric resistivity, apparent density, and porosity. The results show that the 80% Cu–3% Ni–17% TiN electrode at 18 MPa had the highest hardness (124.38 HV) and the lowest electric resistivity (0.39188 cm), while the specimen increased Cu with a ratio of 85% Cu–3% Ni–12% TiN, and a pressure of 20 MPa was found to have the highest density (8.5472 g/cm3) and the lowest porosity (6.2922%). As a further confirmation of the above results, the X-ray diffraction (XRD) patterns of the surfaces of the specimens exhibited major phases that supported the ternary Cu–Ni–TiN phase. However, we also achieved the successful use of Cu–Ni–TiN electrodes as a titanium source (as an alternative to the conventional metal powder) to provide a novel approach to fabricating composite electrodes through the EDM process.

Optimization of electrochemical etching process for manufacturing of micro electrodes for micro-EDM application

Application of Micro-Nano scale Electrical Discharge Machining is rapidly growing in manufacturing of metal products irrespective of its hardness having geometric features in range of micrometer to nanometer scale. To achieve such small geometrical features, smaller dimensional tool electrode is required. However fabrication of this tiny electrode with desired dimension and also handling of such tiny electrodes is a primary aspect that needs to be investigated systematically to use the Micro-Nano scale EDM in batch production of micro parts. In this work authors investigate the application of electrochemical etching process for fabricating EDM electrodes smaller than 10 µm. While the smallest electrode fabricated with the optimized parameter is 3.33 µm, their performance as electrode in micro-EDM has been studied systematically. To the best of authors’ knowledge such studies are not reported in the published literatures. However, the fabrication of such smaller size features by applying alternating current in ECE has been attempted previously but not for micro-EDM applications.

Development of the Technology for Manufacturing a Combination EDM Electrode by Rapid Prototyping

Purpose of research is to develop a methodology that allows designing EDM electrodes applying advanced computer-aided design (CAD) systems by forming the tool’s working surface with geometry which is inverse equidistant to the geometry of a given workpiece taking into account the EDM gap, working translation or translation-rotational motion of EDM electrodes, the value of the layer of conductive coating based on the technological parameters of the processing procedure. It is also necessary to propose, implement and formulate technological guidelines for manufacturing EDM electrodes from dielectric materials by additive techniques with the subsequent formation of a conductive layer on them; the value of the layer should ensure the flow of working electrical processes in the EDM gap and the necessary tool life. This will make it possible to expand the scope of application of combination EDM electrodes as applied to combined processing techniques which are characterized by a wide variety of working surface shapes, which correspond to the geometry of the workpiece, which is not limited by the degree of curvature, has by far lower cost and high processability when creating a special tool for pilot and single manufacturing.Methods. When carrying out the work, theory of the classical laws of mechanical engineering technology, electrical processing techniques, the known laws of rapid prototyping and additive technologies were used.Results. The theoretical foundations and the technology for manufacturing combination EDM electrodes by rapid prototyping have been developed and a methodology for calculating and designing the working part of EDM electrodes has been proposed taking into account the geometric parameters of the machined surface and a variable EDM gap value.Conclusion. The mechanism of EDM electrode design by means of digital prototyping in modern CAD systems is justified taking into account the features of the workpiece geometry, EDM gap and metallization material.

Application of a Cold Spray Based 3D Printing Process in the Production of EDM Electrodes

Cold spray process principles allow the production of near-net-shape metal parts with a fast layer deposition by using 3D printing techniques via supersonic 3D deposition (SP3D). This innovative additive manufacturing process allows an easy and quick production of copper and aluminium parts with future possibilities to expand materials and alloys. The speed and materials enable the application of this cold spray based 3D printing process for the production of tools. In this paper, Electrical Discharge Machining (EDM) electrodes were fabricated by using SP3D to investigate its application in tool production. Requirements for the materials of electrodes and some existing solutions for the production of EDM electrodes with additive manufacturing methods are described first. The fabrication and experimental results are then presented for 3D printed copper EDM electrodes that were tested by using St 37-2 (DIN 17100) steel as the workpiece.

Performance Analysis of Rapid Tool in Electrical Discharge Machining During Machining of Titanium Alloy (Ti6Al4V)

Titanium and its alloys are a class of metallic materials having high strength to weight ratio with excellent properties of resistance to temperature, corrosion and oxidation. These properties increase their use in aerospace, chemical and biomedical industries. Electrical discharge machining (EDM), a non-conventional machining process, is the most suitable process for the machining of titanium and its alloys. Generally, tool electrode for EDM application is prepared through various conventional and non-conventional machining processes. The cost of production of EDM electrodes accounts for more than 50% of the cost of the final product. Therefore, additive manufacturing (AM) technology can be suitably applied for direct manufacturing of the complex EDM electrodes. Selective laser sintering (SLS) is one of the appropriate AM processes for preparation of EDM tool electrode. In the present work, machining performance of the AlSi10Mg tool electrode produced through AM process along with copper and brass tool electrodes have been studied considering titanium alloy (Ti6Al4V) as work piece material and commercial grade EDM 30 oil as dielectric fluid. In addition to the tool electrodes, two more EDM parameters such as pulse-on-time (Ton) and discharge current (Ip) have been considered. Four performance measures like material removal rate (MRR), tool wear rate (TWR), average surface roughness (Ra) and surface crack density (SCD) are used to assess the machining performance. In order to reduce the number of experiments, design of experiment (DOE) approach like Taguchi’s L9 orthogonal array is used. Since the performance measures are conflicting in nature, grey relational analysis (GRA) is used to convert four performance measures into an equivalent single performance measure. The best parametric condition is reported for optimal grey relational grade.