Copper Tool Research Articles

Optimization of Electric Discharge Machining of Al/Al2O3 Metal Matrix Composites using MOPSO

In this article, Response Surface Methodology (RSM) and Multi-objective Particle Swarm Optimization (MOPSO) were used to optimize the output response of Material Removal Rate (MRR) and Surface Roughness(SR) of die-sinking Electrical discharge machining (EDM). An aluminum based metal matrix composites, reinforced with alumina, prepared by stir casting, was used for machining on EDM by Copper (Cu) and Titanium (Ti) tool. Box- Behnken Design (BBD) approach of RSM was used to design the experiment by considering four input factors at three levels. This developed model for multi-objective optimization by MOPSO and an RSM-based multi-objective optimization was also designed for input parameters. And it was found that the MOPSO technique was easy and valuable for parametric optimization of EDM. From MOPSO, optimized input parameters for machining of AMMC using Cu tool are current 4A, Voltage 60V, pulse on-time 100 µs, and duty factor 6. From MOPSO, optimized input parameters for machining of AMMC using Ti tool are current 4.241658A, Voltage 60V, pulse on-time 100 µs, and duty factor 4. The confirmatory test found that MRR and SR decreased by 63.86 % and 53.083% for the Cu tool, respectively, for MOPSO compared to RSM optimize value.

Enhancing EDM performance characteristics of Inconel 625 superalloy using response surface methodology and ANFIS integrated approach

The objective of the present work is to find out the optimal level as well as the influence of the electrical discharge machining (EDM) process on material removal rate (MRR), surface roughness (SR), and tool wear rate (TWR). The machining is carried out on Inconel 625 superalloy by using a copper tool electrode in a kerosene submerged medium. The optimum level of input parameters such as current, pulse on time (Ton), pulse off time (Toff), and gap voltage are calculated to achieve maximum MRR and minimum SR and TWR. L27 orthogonal design is used to perform the experiments and optimum levels of MRR, SR and TWR have been obtained by the response surface methodology (RSM) and adaptive network-based fuzzy inference system (ANFIS) approach. Analysis of variance (ANOVA) is used to identify the significant and non-significant parameters. For implementing, RSM methodology, the Design Expert 13 software was used for the optimization and modelling of the experimental data. MATLAB R20b software was utilized for developing the ANFIS model. It is found that the pulse on time (Ton) and pulse off time (Toff) are the significant parameters for MRR and SR and more wire wear increases as the value of pulse on time (Ton) increases. The obtained quadratic RSM model is found significant for MRR, SR, and TWR. Similarly, ANFIS proved to be accurate for the optimization of output responses with model accuracy percentages noted as 95.55% for MRR, 90.35% for TWR, and 97.82% for SR. The obtained results show that the predicted values and experimental values are very well suited for the proposed objective. The obtained data can be utilized for the EDM industry during the machining of Inconel alloy.

Refining the chronology of North America's copper using traditions: A macroscalar approach via Bayesian modeling.

North America’s ancient copper use, predicted to originate as early as 9000 cal BP, represents the earliest use of native copper for utilitarian tool production in the world. Although recent work has focused on establishing the first use of copper in the western Great Lakes region, little attention has been paid to determining the age ranges of subsequent copper using groups or to the identification of broader trends in copper use during the Archaic Period (10,000–3000 RCYBP). Here we address this issue by applying Bayesian modeling to a comprehensive suite of 76 radiocarbon dates directly associated with copper use. Our results identified two distinct peaks in copper usage, ca. 5500 cal BP and ca. 3300 cal BP. Age ranges for the three Archaic Period traditions and practices associated with copper use of the western Great Lakes are revised using modern calibration curves. Bayesian revisions of age ranges from sites where copper tools and/or production debris have been found provide insight into the historical relationships between, and cultural interactions among, these early copper using groups. This study provides an updated, refined chronology based on the most recent calibration curve (IntCal20) for the varied cultural contexts of copper use across the western Great Lakes.

Influence of Adaptive Gap Control Mechanism and Tool Electrodes on Machining Titanium (Ti-6Al-4V) Alloy in EDM Process.

Titanium alloy is widely used for orthodontic technology and easily machined using the EDM process. In the EDM process, the workpiece and tool electrode must be separated by a continuous air gap during the machining operation to generate discharge energy in this method. In the present study, an endeavor was made to analyze the effects of a servo feed air gap control and tool electrode in the EDM process. The developed mechanical setup consists of a linear action movement with zero backlash along the X-axis, which can be controlled up to 0.03 mm. It was observed that the suggested air gap control scheme can enhance the servo feed mechanism on a machining titanium alloy. A tungsten carbide electrode can enhance the surface measures owing to its ability to produce tiny craters with uniform distribution. Since it produces a little crater and has a higher melting point, a tungsten carbide electrode can create lesser surface roughness than a copper tool and brass tool electrode.

Optimal Linear Estimation (OLE) Modeling Supports Early Holocene (9000–8000 RCYBP) Copper Tool Production in North America

The discovery and development of metal as a tool medium is a topic of global interest. A fundamental research goal involves establishing the timing of human experimentation with naturally occurring copper ore, which is commonly associated with sedentary, agrarian-based societies. However, in North America, there is well-documented millennia-scale exploitation of copper as tool media by small, seasonally mobile hunter-gatherer groups in the western Great Lakes. Archaeologists have suggested that Late Paleoindian groups may have begun using copper as a tool medium almost immediately after they entered the Lake Superior basin. However, only a few radiocarbon dates support such early use of copper. Here, we use optimal linear estimation modeling to infer the origin date for copper tool production in North America. Our results show that the invention of copper as a tool media likely occurred shortly after the first pioneering populations encountered copper ore during the Pleistocene-Holocene transition. The origin dates modeled here (ca. 8100 RCYBP) reveal several important features about the behavior of pioneering hunter-gatherer populations. Moreover, our results suggest that this phenomenon represents the earliest known use of metal for utilitarian copper tool production.

Multiresponse optimization of EDM parameters for tungsten carbide using TGRA

Electro Discharge Machining (EDM) is a non-conventional machining process in which material is removed by heat (thermal energy) generated by the spark. Electric energy is the main source of generating a spark that is further used to machine hard-to-cut materials. In this study, the dielectric fluid of EDM is suspended with powder particles, copper (tool) is used as a cathode and tungsten carbide (workpiece) is used as an anode. WC has large applications in tool manufacturing, making moulds, dies, and nozzles because of its high strength and hardness. The powder mixed with suspended particles has numerous effects on the surface finish of the specimen. The effect of input parameters such as current (I), powder concentration, and pulse on (Ton) are studied on surface roughness (Ra) and material removal rate(MRR). Taguchi-based orthogonal array L9 is used for experimentation, and grey relational analysis (GRA) is used for simultaneous optimization of output characteristics. For MRR, I and Ton time are the significant parameters. All input parameters are significant for Ra, and the SiC concentration highly influences Ra. For MRR most contributing factor is the pulse on time followed by current and concentration. The optimal parameters setting for Ra and MRR is current at 7A, pulse on at 80 µs and concentration at 10 g/l. It is found experimentally that powder characteristics significantly affect machining characteristics. MRR increases with the increase in I and Ton time and shows oscillating behaviour with concentration. The Ra value increases slightly with the I and Ton time and a sharp decrease in Ra value with the increase in concentration.

Effect of cryogenic treated tool electrode during electric discharge drilling (EDD) of Inconel 800

Inconel 800 is widely used material for construction of equipment and which requires corrosion resistance, heat resistance, strength, and stability. These properties make them potential material for components in aerospace industries, gas turbine etc. The conventional drilling in Inconel 800 sometimes become uneconomical because of low productivity, poor quality and inaccurate geometry. Electric Discharge Drilling (EDD), a variant of EDM, is one such process which can produce high accuracy holes, thus improving overall productivity and reducing the cycle time. This paper describes an experimental study on EDD of Inconel 800 using self-developed EDD set up. The holes were drilled using copper tool electrode. The effect of tool electrode treatment (cryogenic and untreated), discharge current (Id), pulse-on time (TON), gap voltage (Vg) and tool electrode speed (N) on material removal rate (MRR), electrode wear rate (EWR) and radial overcut (ROC) have been studied. The experimental runs were carried out using L18 (21 × 34) orthogonal array and result were analyzed using Taguchi’s methodology. It was observed that the optimal parameter setting for MRR are TET (cryogenically treated), Id (15A), TON (120 µs) and N (200 rpm), for EWR- TET (cryogenically treated), Id (9A), TON (120 µs) and N (200 rpm) and for ROC- TET (cryogenically treated) and Id (12 A). It was also observed that with the use of cryogenically treated tool electrode an appreciable improvement in the MRR by 9.89%, EWR by 21.73% and ROC by 36.15% is achieved, which confirm the viability of using the cryogenically treated tool electrode and relevance to industry.

On the Influence of Electrical Discharge Drilling Parameters and Per-formance Measures of Inconel 718 Superalloy - a Study

In order to achieve higher productivity and product quality, the investigation of machining parameters on Electrical Discharge Drilling and surface characteristic analysis are most critical for manufacturing industries. The intention of this article is to assess the impact on performance matrices including Material Removal Rate, and Surface Roughness of input factors of peak current, pulse-on and off duration while drilling with a rotary hollow copper tool on Inconel 718 under Tungsten powder suspended kerosene. Analysis of Variance has been implemented using MINITAB release 18 software to identify the most significant input factors. An Artificial Neural Network was used for validating the experimental results of the drilling process. The additional intention of this research is to discover the significance of influencing input parameters and analyze the quality surface of the workpiece were observed by microscope tests. The experimental results indicated that the peak current and pulse-on period have an effect on the performance of the drilling process considerably.

Influence of different tool electrodes on machining of oil hardened non shrinking steel using die sink electric discharge machine

Tool steel has been a crucial material for many industrial applications and manufacturing of machining tools and milling cutters although very few machining techniques are available for machining of these materials. In this study, the performance of copper and brass tool electrodes on the die sink electric discharge machining of oil-hardened non shrinking steel (OHNS) has been evaluated. Current, pulse on time, and pulse off time were considered as the factors and the responses as material removal rate (MRR) and tool wear rate (TWR). The design of experiments technique namely the Box-Behnken design (BBD) under response surface methodology (RSM) was utilized. The response models were developed for MRR and TWR for brass and copper tool electrodes. The MRR and TWR for brass and copper tool electrodes were compared and represented graphically. The results show that current is the significant factor affecting both MRR and TWR and compared to brass, copper is a suitable electrode for die sink electric discharge machining of OHNS. The confirmative tests validate the developed response models of MRR and TWR.

EARLY BRONZE AGE METALLURGY AT MURAT HÖYÜK, EASTERN ANATOLIA: ARCHAEOMETRICAL ASSESSMENTS OF A FIGURINE AND A METAL TOOL

Murat Höyük lies on the bank of the Murat River in Solhan district of Bingöl province in Eastern Anatolia. This study presents archaeometrical analyses of a unique metal figurine and a metal tool recovered in situ during the 2019 Murat Höyük Excavations, the first systematic archaeological excavation project in Bingöl. Four cultural layers (Medieval, Middle Iron, Early Iron, and Early Bronze Age) were documented at the site, where the earliest settlement is dated to the EBA III (2500-2200 BC). The metal figurine and tool were found in this earliest phase (IV), where stone mould fragments and a crucible were also found in associated contexts. Portable XRF (p-XRF) analyses performed on the figurine, and p-XRF and metallography analyses conducted on the copper tool revealed that metals used in the manufacture of these artefacts were smelted from different polymetallic copper ores. Additionally, production process of the objects was examined in this study. A holistic evaluation of finds related with metallurgy at Murat Höyük reflects cultural affiliation with the Upper Euphrates Basin in terms of material choice and production technology. The present study on Murat Höyük metal finds provide new insight into Early Bronze Age metallurgy, belief systems, and art in Eastern Anatolia.

The Effect of Electrical Discharge Machining Total Heat Generated on White Layer Thickness (WLT) and Fatigue Life for Die Steel

The present paper concerns with studying the high complexity nature of the EDM multiple discharge analysis transformed into a feasible solvable mathematical model for the die steel workpiece type AISI D2, the copper and graphite materials electrodes, and the kerosene dielectric by setting the Transient Thermal and the Multiphysics analyses domain loads models using the ANSYS 15.0 finite element analysis. Two load steps modeled the entering setting time analysis, six sub-periods setting time cycle, four heating, and two cooling periods, six transient temperature values, and four transient thermal convection models. The radius spark (discharge channel), the total number of discharges sparks, the total heat power generation, the absorbed heat flux fractions by the electrodes, the workpieces and kerosene fluid dielectric, the heat-affected zones (HAZ), the hard white recast layer thickness (WLT) and properties, the workpiece fatigue safety factor and life after EDM machining were determined and simulated. The thermal model errors compared with theoretical calculations and a modeled predicted equation were also deduced and verified. The experimental results evinced that the maximum total heat flux generated using the graphite material electrodes is (2.619E+009 W/m2) which is higher than when using copper material electrodes by (82.4%), while the minimum value of the white layer thickness (WLT) after EDM machining using graphite tool electrodes is (8.34 μm), which it gives an improvement comparing with using of copper tool electrodes by (40.0%). The macrographic and microstructure evaluation manifest that the discharge spark craters sizes when using graphite tool electrodes reached their sizes. The maximum fatigue stresses and fatigue safety factor when using copper tool electrodes are (240 MPa) and (0.89) which is higher by a value of (3.35%) and (3.45%) comparing with the using of graphite electrodes, respectively.

Study of Electrical Discharge Machining Parameters on Stainless Steel Using Copper Tool Electrode and Its Effect on the Structure and Electrochemical Properties

In this work, the effect of the presence and the diffusion of the Copper from the tool electrode onto the EDMed stainless steel (SS) surface have been investigated by electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD), Quantometer analysis, and Optical microscopic observations. The Taguchi method was used to study the effects of Pulse-on time (ton), Pulse-off time (toff), discharge current (I), and overall machining time (τ) on chemical composition, microstructures, micro-cracks, and electrochemical corrosion of EDMed stainless steel workpieces. The results show that the variation of machining parameters changes the chemical composition of the workpieces. By increasing the discharge current and decreasing the Pulse-on time, the copper and the carbon diffuse onto the surface of the workpiece. Consequently, the chemical composition of the workpiece surface changes, which leads to an increment of the corrosion resistance. The XRD showed the formation of Fe2C, Cr3C2, and CuNi. In addition, at higher values of discharge current and ton/toff ratio, the micro-cracks propagate on the surface of the workpiece.

Новые данные о начале функционирования Приуральского (Каргалинского) горно-металлургического центра

The article summarizes the data on the initial stage of metal production in the Southern Urals of the Bronze Age. Lots of Yamnaya culture burial mounds with copper items inside were excavated near the Kargaly deposit in the Orenburg oblast. The variety and originality of tools forms indicate the independent nature of the Ural metallurgy in the early Bronze Age. The authors present new data that allows us to reconstruct the process of metal production at the Repin (early) stage of the Yamnaya culture and explain the beginning of this process by the development of the Kargaly copper ore deposit. Excavations of the Turganik settlement were carried out. Cultural layer 5 of the early Bronze Age is dated to 3800–3360 cal BC. It is characterized by ceramics and other artefacts of the Repin type. Fragments of Kargaly copper ore, slags and copper tools (knife, awls) were found in the layer. The traceological analysis of about approximately 100 items made of stone and animal bones was performed. 41 of them are related to metallurgy and metalworking. They represent tools of all metallurgical production stages, starting from metal extraction from ore to the processing of the finished copper product. Functional groups of products such as ore mortar, ore crushing hammers, casting molds, forging hammers, anvils, edges leveling tools, sharpening stones, and others have been identified. Stone artifacts from the burials were also studied, including ore crushing and forging hammers. No mining tools were found at the settlement. It is concluded that the ore was extracted and processed at the Kargaly deposit, located 70 km to the east, and then delivered to the settlement as an enriched concentrate. The settlement was seasonal. Metallurgical activity here took its place in the summer, since the main type of economic activity was nomadic pastoralism.

Optimisation of EDM Parameters for Cryogenically Treated EN31 Steel with Copper Tool

EDM has been replacing drilling, milling, grinding, and other traditional machining operations and is now a well-established machining option in many manufacturing industries throughout the world and is capable of machining geometrically complex or hard material components, that are precise and difficult-to-machine such as heat-treated tool steels, composites, superalloys, ceramics, carbides, heat resistant steels, etc. During machining done over EDM machine, with the workpiece, even the tool wears out. This tool wear is not desired as it changes the tool geometry. To overcome this hurdle, cryogenic treatment is carried out for workpiece material before machining. This report presents the optimization of EDM process parameters such as pulse on-time (Ton), pulse off-time (Toff), and Current (I) to obtain the greatest material removal rate (MRR) and less surface roughness (Ra) of EN31 steel with copper as the working electrode for machining.

Effect of Powder Particle Concentration and Tool Electrode Material amid Zinc Powder-Mixed µEDM of Biocompatible Mg Alloy AZ91D

Magnesium (Mg) alloys exhibit high strength and biocompatibility, coupled with a unique characteristic that is the ability to degrade over time. These characteristics of Mg alloys led to the development of several biodegradable medical implants such as screw, pin, and plate. Powder-mixed micro-electric discharge machining (PM-μEDM) was found to substantially improve the surface and metallurgical properties of biodegradable alloys and therefore, it was used in this study to investigate the machinability of Mg alloy AZ91D. PM-μEDM was performed at varying zinc (Zn) powder particle concentrations (0 to 8 g/l) using copper and brass tool electrodes. The effect of these input control variables on the machining time, dimensional deviation, and characteristics of the machined surface was experimentally examined. The machined surfaces were primarily analyzed by field-emission scanning electron microscope, energy-dispersive spectrometry, and x-ray diffraction (XRD). The findings showed a significant reduction in the machining time and dimensional deviation during PM-μEDM at 4 g/l powder particle concentration using the copper tool electrode. Moreover, the presence of resolidified debris, powder particles, and formed metal oxides and carbides in the recast layer, produced with the aid of the copper tool electrode at 4 g/l powder particle concentration, exhibited a considerable surface modification.

Arsenical copper tools of Old Kingdom Giza craftsmen: First data

This study deals with the remains of metal objects from the settlement of workers living and labouring at the Egyptian site of Giza in the reigns of Dynasty 4 Kings Khufu and Khafra (c. 2500–2450 BCE). It provides the first detailed set of data on copper tools of the craftspersons working with wood, limestone, textile, etc., focusing on the major and trace element analyses, lead isotopes and microstructural description. Arsenical copper is again confirmed as a material practically used in the Old Kingdom, with arsenopyrite from Eastern Desert proposed as a source of arsenic. The CuAgAs needle 20966 has similar lead isotopes as two pieces of Predynastic Egyptian metalwork and litharge from late Uruk site Habuba Kabira (Syria), being probably a recycled specimen of earlier material connected to silver production. With 15 objects analysed in detail, it is for now the largest Old Kingdom corpus of metal objects from the settlement context.

The Role of Functional Efficiency in the Decline of North America’s Copper Culture (8000–3000 BP): an Experimental, Ecological, and Evolutionary Approach

The copper-using cultures of North America’s Archaic Period (10,000–3000 BP) have long been an archaeological enigma. For millennia, Middle and Late Archaic hunter-gatherers (8000–3000 BP) around the Upper Great Lakes region made utilitarian implements out of copper, only for these items to decline in prominence and frequency as populations grew and social complexity increased during the Archaic to Woodland Transition. From a cultural evolutionary perspective, the trajectory of North America’s copper usage presents a conundrum, as it is generally assumed that “superior” tools, i.e., metals, will replace inferior ones, i.e., stone. For well over a century, scholars have pondered the reason for the demise of copper technology that was once a wide-spread phenomenon. To address this question, an extensive archaeological experimental program was conducted which compared replica copper tools (spear points, knife blades, and awls) to analogous ones made of stone or bone to assess whether relative functional efficiency contributed to the decline of utilitarian copper implements. Here, the results of this three-part research program are presented in concert with population dynamics and ecological change to paint a broader picture of the complex interrelationships between the social, ecological, and technological spheres of past human behaviors. The synthesis of these approaches reveals that functional explanations—derived from experimental archaeology placed in an evolutionary framework—can shed much light on the trajectory of metal use in the North American Great Lakes.

Influence of process parameters on MRR and taper cut in micro drilling of SS304 using electrochemical machining

Electrochemical machining is a modern way of removing the materials by using electrochemical dissolution technique. This method is used to drill the holes ranging from macro to micro scale with good quality which are prime demand in electronics, automobile and many more industries. In this experimental work, SS 304 workpiece was drilled using copper and brass tool of 500 µm each. In order to investigate the effect of machine variables such as voltage, pulse on and pulse off time on material removal rate and taper cut, as per orthogonal array nine experiments were conducted for each tool. The results of both the tools were compared and found that at lower level copper tool performance was better and at higher levels brass tools performed well. The interaction effect of parameters were also studied for both the tools and concluded that there is no specific trend for interaction.

Effect of nichroloy coated electrode on machining performance of electrical discharge machining using Inconel 625

EDM is an important method for machining of hard and difficult to machine materials by other traditional methods such as titanium alloy, tool steels, carbides, super alloys, heat resistant steels etc. It has applications in die making, mold making industries, automobile industries, aerospace etc. EDM machining can be used for machining of difficult geometry and intricate shape components. In present work, INCONEL 625 work material is used. This material has wide range of applications in seawater components, petrochemicals, aircraft ducting system, jet engine applications etc. Two tools are used one is copper and other is nichroloy coated copper tool. The experiment is conducted using Taguchi design. Input process parameters are pulse on time (Ton), duty cycle (dc), Peak current (Ip) and Gap voltage (Vg). Material removal rate (MRR) and surface roughness (SR) are response characteristics. Influence of input parameters over the responses are studied. Analysis of variance (ANOVA) is used to find the percentage contribution of input parameters. Grey relational analysis (GRA) is used which provides optimized result. It is observed that copper tool produces higher MRR and nichroloy coated tool produces fine surfaces. Optimal parameter setting is Ton = 500 µs, dc = 9, Ip = 25 amp and Vg = 20 V.

Upoređivanje karakteristika površine i mikrotvrdoće AISI D2 alatnog čelika i LM13 legure aluminijuma obrađivanih postupkom suve elektro-erozione obrade (proces zelene obrade)

In this experimental work, the micro structure and the micro hardness of the surfaces machined under the dry EDM process is analyzed for AISI D2 tool steel and LM13 aluminum alloy. The experiments were conducted using copper tool electrode. Few modifications were made in the tool for conducting the experiments under dry EDM process. Discharge current, pulse on time, voltage, pressure, tool rotational speed and the duty factor were used as the various process parameters and their influence over the micro structure and micro hardness of the machined surfaces were analyzed. Better results were observed in the dry EDM process for AISI D2 tool steel, whereas dry EDM process did not reveal appreciable results for LM13 aluminum alloy.