Arc Current Research Articles

Effects of postdeposition annealing under atmospheric conditions on the properties of amorphous conductive W-doped In2O3 deposited on glass substrates by reactive plasma deposition with direct current arc discharge

Effects of postdeposition annealing under atmospheric conditions on the properties of amorphous conductive W-doped In2O3 deposited on glass substrates by reactive plasma deposition with direct current arc discharge

Simulation of metal nanoparticles growth in methane atmosphere of arc discharge: comparison to experiment

Abstract A direct current arc discharge in a methane atmosphere is a scalable and sustainable method to produce metal-carbon core–shell nanoparticles and single-walled carbon nanotubes, where a metal catalyst can be continuously supplied through evaporation of an anode made from the catalyst material. The size of catalyst particles is of critical importance as it can affect the synthesis yield and properties of nanotubes and core–shell nanoparticles. This study presents a numerical model describing the formation and growth of metal particles for the conditions representative of the arc discharge with an evaporating iron anode at near-atmospheric pressure of a methane-rich atmosphere. The model incorporates carbon adsorption to the metal surface and explains the limiting effect of carbon coverage on the size of metal nanoparticles. The predicted particle sizes are compared with experimental observations. The model also predicts higher concentrations of metal particles with the increasing partial pressure of methane.

Plasma Torch Height Tracking Based on Rolling Grey Prediction

Among the parameters influencing plasma arc cutting, arc current, cutting speed, and plasma torch height act as the main factors. Among them, the plasma torch height plays an important role in improving the kerf width and cut quality, and the automatic control of the plasma torch height is essential due to the deformation of the workpiece during the cutting process. Therefore, according to the surface condition of the workpiece during plasma cutting, it is required to have automatic control so that the gap between the plasma nozzle and the cut workpiece remains constant. The plasma torch height control system in this paper consists of the sensing, controller, prediction, and stepper motor control system of the plasma torch height. Here, the rolling mode grey prediction algorithm is applied to predict the next state for the cutting forward direction and to control the previous data continuously updating. It is shown by the Simulink results of Matlab that the plasma torch height tracking with rolling grey prediction has better tracking accuracy than the general PID control method. In addition, the comparison between the plasma torch height tracking experimental results using the rolling grey prediction based method and the tracking experimental results using the general PID control method in the cutting test showed that the variation of the arc voltage is less, the cutting width is smaller, and the tracking performance is improved.

Advanced temporal analysis of anode activity during mode transitions in high current vacuum arcs

Abstract Anode activity in high current vacuum arcs leads to the formation of various high current modes and transitions between them. Intense material evaporation during the anode spot mode and formation of a neutral vapour cloud during the anode plume mode modify the arc plasma properties and, hence, can have a crucial impact in applications, like e.g. reduction of interruption performance of switching devices. The influence of anode mode appearance on arc plasma parameters and on anode surface temperature was studied in detail by a novel optical diagnostic technique—intensified video optical emission spectroscopy. Employing advanced diagnostic methods, the ground state density, excitation temperature and pressure profiles close to the anode surface have been determined. For the anode plume mode, higher copper vapour pressure was found in the plume shell compared to its core. The copper ion density distribution shows a maximum outside of the plume shell. Consequently, a higher electrical conductivity in the surrounding area of the plume might be expected, i.e. the arc current flows around the plume rather than through it. Analysis of the temporal evolution of electrical and optical signals reveals that voltage jumps and drops during the mode transitions are accompanied by noticeable changes in the anode surface temperature. Thus, the formation of the anode plume leads to temperature lowering while the transition to the anode spot mode is accompanied by a temperature increase. In general, a clear correlation between electrode surface temperature and arc voltage in the case of constricted anode attachment is found. The results of this study give new insights into anode plume properties and consequences of anode mode transitions. Reversible mode transitions and correlations between arc voltage and anode surface temperature, as well as changes in the current path during anode plume mode, have to be considered as factors for optimization of electrode design and choice of materials for switching applications.

Optical emission spectroscopy of breaking arc plasma between consumable electrodes

The investigation focuses on the optical emission spectroscopy of plasma generated by breaking arc between single-component Cu and composite Cu-W electrodes manufactured using shock sintering technology at temperature of 750°C. The electrodes were subjected to arc currents of 4, 50, and 104 A. Optical emission spectroscopy with high spectral and temporal resolution was employed to investigate the plasma with copper and tungsten vapour admixtures. The temporal evolution of temperature in the plasma was determined by the Boltzmann plot technique based on the emission intensities of Cu I spectral lines. Temporal evolution of electron densities were determined from the full width at half maximum of Cu I 515.3 nm spectral line. These initial plasma parameters integrated over the volume of breaking arc were utilized to calculate the temporal evolution of plasma compositions and contents of metal vapours admixtures in discharge gap.

Forming characteristic analysis in twin tungsten electrode – Wire electrode indirect arc based additive manufacturing

In this study, the forming characteristics of twin tungsten electrode – wire electrode indirect arc (TTWIA) based additive manufacturing were preliminarily investigated. Arc shape, droplet transfer behavior, molten pool temperature field, and molten pool flow state were obtained respectively. Results showed that the increase of arc current enhanced the coupling degree of TTWIA arc, and promoted the detachment of the droplet from the wire, which contributed to streaming spray transfer of the droplet. Besides, the temperature and fluidity of the molten pool both increased with the increase of the arc current due to the increasing temperature of the arc, enthalpy carried by the droplets, and driving forces acting on the molten pool. Moreover, the driving forces acting on the liquid metal in the deposited layer achieved equilibrium and a stable molten pool was acquired only when the arc current was selected appropriately, which resulted in a well forming quality of the deposited part with a lower surface roughness and a higher material utilization rate.

In situ Fe-doped thin carbon wires via AC high voltage arc discharge

This study explores the controlled, continuous production of thin carbon rods between graphite electrodes (continued electrode deposits) during an arc discharge of high voltage alternating current with a frequency of 50 Hz in liquid paraffin, along with in situ doping of the resulting material using a suspension of liquid paraffin and iron powder ( <10 μm). The surface morphology of the obtained carbon rod nanomaterials was characterized using scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), scanning transmission electron microscopy (STEM) with EDX chemical composition analysis, X-ray microtomography (micro-CT), and atomic force microscopy (AFM). The AFM technique in scanning thermal microscopy (SThM) and conductive probe (CP) modes was employed to determine the temperature and electrical conductivity of the obtained nanostructures. Qualitative analysis was conducted using Raman spectroscopy, X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). This simple system for producing thin, stable carbon wires (< 1.2 mm thick) enables efficient and low-cost production and doping of these materials. The high-voltage alternating current (HVAC) arc discharge method for growing controlled, metal-doped electrode deposits presents a new approach to producing inexpensive, porous carbon nanomaterials for various scientific and technological applications.

Internal cylindrical cathode arc deposited Cr coatings on the interior of slender tube: The influence of arc currents

In this study, a novel internal cylindrical cathode arc device with electric-field assistance is proposed to address the issue of uniform coating on the interior of a slender tube. The relative average deviation of Cr coating thickness has been reduced to as low as 0.53 %, indicating high uniformity in axial thickness of the coatings. The effect of different arc currents (25–55 A) on the structure and surface properties of the coatings is investigated. The thickness, micro-structure, surface roughness, nano-hardness, friction and wear, adhesion between the coating and substrate as well as corrosion resistance of the deposited coatings are measured by a scanning electron microscopy, atom force microscopy, X-ray diffraction spectrometer, nano indenter, friction and wear instrument, scratch and indentation apparatus and electrochemical instrument, respectively. The results suggest that the proportion of macroparticles increases with arc current. Additionally, the macroparticles exhibit an atypical oblate pattern. This may lead to weaker, more fragile regions that are prone to flaking. Consequently, larger arc current gives rise to the deterioration in the tribological properties, adhesion between the coating and substrate, and electrochemical properties of the coatings. This study provides a feasible solution to obtain extremely uniform Cr coatings on the interior of slender tube by using the axially cylindrical cathode arc ion plating. At the same time, minimizing the arc current is beneficial to improve the performance of the coatings.

Evaluating porosity formation in gas metal arc directed energy deposition of an aluminium alloy

Porosity formation in gas metal arc directed energy deposition of aluminium alloys is a critical challenge as it affects the structural integrity of build parts. An experimental investigation is reported here to examine the influence of energy input on pore size and area fraction in single- and multi-layer build samples of an aluminium alloy for short-circuiting and pulsed current gas metal arc. The energy input is estimated from real-time current and voltage transients. The porosity distribution in deposited samples is measured using an image segmentation approach. The pulsed current mode yielded 16–22% lower pore area fraction in comparison to short-circuiting mode. For the range of process conditions considered, an increase in energy input reduced pore area fraction significantly.

Nanoporous Amorphous Silicon Thin Films Fabricated with Helium Plasma for Lithium Ion Battery Application

Lithium-ion batteries (LIBs) have the advantage of being compact and lightweight, and significant advancement has been made commercially and acadmically in recent several decades. It is essential to develop a new anode material that can replace graphite to further increase capacity, and various materials are being investigated including silicon (Si). Among them, Si is being studied as a candidate for a new anode material because its theoretical capacity per weight is about ten times higher than that of graphite and it is abundant and inexpensive. Among them, thin film approach has achived a great success and good electrochemical performance in terms of specific capacity and cycle life. One of the challenging issues with the thin film approach is that thick films, typically 500 nm, cannot maintain the performance identified in thinner film samples. In this study, we introduce a novel method using helium (He) plasma to form porous Si thin film. Different magnetron sputtering, in the present plasma-assisted method deposit Si atoms on the surface while the surface is exposed to the He plasma. It is shown that plasma assisted method can be another candidate to form nanoporous amourphous Si thin film for high performance LIB application.Silicon thin film was formed in the linear plasma device called Co-NAGDIS. The plasma is produced by a direct current arc discharge using a meander lanthanum hexaboride cathode heated with a Joule current. The magnetic field by two solenoidal coils formed a cylindrical plasma. Helium gas was used for the discharge gas, and the He flux was measured with a reciprocating electrostatic probe. Difference from the magnetron sputtering, which also uses plasma and has been widely used to fabricate Si layer for LIB application, is in the fact that particles (He ions) of high-density plasma, typically ~1018 m-3, are also implanted together with Si atoms on the substrate. Copper (Cu) substrate is equipped to an air-cooled sample stage, of which temperature can be controlled by changing the flow rate of the air. Silicon sputtering plate is installed 1 cm away from the substrate and biased to ~-100 V to induce sputtering. The sputtered Si atoms deposit to the substrate together with the He ions. The deposition time was 90 min for all the samples. The porosities of the two samples shown in this work (Si1 and Si2) was ~0.5, and the thickness was ~1.5 micrometer. The sample tempearture during deposition was 523 K (Si1) and 573 K (Si2).Figure shows the discharge capacities of the two samples (Si1 and Si2). Charging and discharging were repeated with C rate of 0.01C for times 1-3, 0.02C for times 4-6, 0.05C for times 7-9, and 0.1C for times >9. They had an initial capacity of approximately 3000 mAh/g, and they retained higher than 1000 mAh/g even after 20-30 cycles. For Si1, the number of charge-discharge cycles was extended to 250 cycles, and the performance of Si1 gradually decreased but still remained 1800 mAh/g after 100 cycles and ~1200 mAh/g at 250 cycles. The surface was observed by scanning electron microscope (SEM), the surface of Si1 and Si2 was almost flat. From cross section observation by a transmission electron microscope (TEM) after a focus ion beam miiling, it was found that there is no clear evidence of He bubbles in the Si deposition layer, but the layer is mainly composed of 100-200 nm diameter clusters, and the density between the clusters is lower. Thermal desorption spectroscopy (TDS) analysis was performed to analyze the behavior of implanted He atoms in Si layer. It was found that He atoms are implanted to the thin film layer. From the Raman spectroscopy, it was found that amorphous Si was formed at 523 K, but it becomes crystal structure at 573 K. The importance of the amorphous structure is well recognized, and it can be said that Si1 showed better performance than Si2 due to its amorphous structure. In the Figure, evolutions of coulombic efficiency (CE) of Si1 and Si2 is also shown. The CE increases in the initial 5-10 cycles and almost constant after then. The averaged CE after 50 cycles for Si1 and Si2 were 99.51 and 98.72%, respectively. The results showed that the plasma implanting method can be a novel method to form amorphous porous thin film for lithium ion battery. Figure 1

Features of the Influence of the Arrangement of Parts in the Chamber of Installation During Vacuum Arc Deposition on the Properties of Coatings

The effect of the spatial arrangement in the physical vapor deposition (PVD) chamber on the composition and properties of coatings is considered using the example of the deposition of the (Ti,Al)N coating. The proposed method is one of the ways (along with varying the arc current of the cathodes and the bias voltage, as well as using alloy cathodes) to change the ratio of elements in the coating, and achieves this across a wide range of values. The three samples were located, respectively, opposite the evaporator with a titanium cathode, opposite the evaporator with an aluminum cathode and in an intermediate position between the two evaporators. The coating was deposited without rotating the turntable. The aluminum content in the coatings decreases from 94.2 at.% for the sample located directly opposite the evaporator with an Al cathode to 10.3 at.% for the sample located opposite the evaporator with a Ti cathode. In the coating deposited on the sample located opposite the aluminum cathode, the formation of a nitrided layer with a thickness of about 250 nm was observed in the substrate. The maximum hardness (32.3 ± 1.7 GPa) belongs to a coating on the sample occupying an intermediate position. The coating on the sample located opposite the aluminum cathode has a hardness of 16.7 ± 0.8 GPa. The coating hardness on the sample located opposite the titanium cathode is 28.5 ± 1.1 GPa. The best fracture strength in the scratch test was observed for the coating on the sample occupying an intermediate position. The nature of the coating fracture in the scratch test was studied. A sufficiently high-quality coating can be obtained without rotating the turntable, and the coating composition can be controlled by changing the position of the sample relative to the evaporators.

Study on Characterization of SrO Aerosols Generated by Optimized Thermal Plasma Torch Aerosol Generator

AbstractPlasma Torch Aerosol Generation System (PTAGS) has been employed to generate nano aerosols with desirable characteristics. The operational parameters of PTAGS installed in the aerosol test facility have been optimized, and aerosols are generated using non-radioactive SrO2 powder. The current-voltage characteristics, electro-thermal efficiency and torch power are studied as a function of the flow rate of the plasma-generating gas (mixture of argon and nitrogen) and the arc current of the plasma torch. The relation of arc characteristics is determined using the Nottingham formulation. Based on this, torch parameters evolved and optimized as 20 kW power, 70% electro-thermal efficiency, 25 L min− 1 flow rate of plasma forming gas, 5 mg min− 1 powder feed rate and for 4–5 min torch operation towards the generation of SrO nano aerosols to achieve 1012 m− 3 and ~ 25 mg m− 3 for the count and mass concentration of aerosol respectively. The initial size distribution of the aerosols is in the few tens of nanometre range (10–40 nm) with a mean diameter of 26 nm (σg = 1.45). Scanning Electron Microscope and Energy dispersive X-ray analysis revealed that the morphology of nano aerosols was nearly spherical and the formation of SrO nanoparticles. A set of PTAGS operational parameters has been standardized to perform further experiments related to reactor safety analysis. PTAGS shall be tuned for aerosol generation in a large facility to achieve the characteristics equivalent to reactor accidental conditions.

Structure and properties of the boride layer of steel using the plasma alloying method

Boration is one of the promising methods for increasing surface hardness and wear resistance, resistance to oxidation and corrosion of mechanical engineering parts. The diffusion saturation process is characterized by a long duration, as well as a shallow depth of the hardened layer. The use of concentrated heating sources can solve these problems. Among the methods of high-energy exposure, the technology of plasma surface alloying should be highlighted. In this paper, the study of the microstructure and properties of the boride layer obtained on steel by plasma alloying is carried out. It is noted that the boron-doped layer has a heterogeneous structure and high hardness. It is noted that the layer obtained after alloying with a current of 120 A has the highest microhardness value and amounts to 859–1265 HV. With an increase in current to 140 A, the microhardness of the alloyed layer decreases and amounts to 761–1048 HV. Increasing the current to 160 A leads to a significant decrease in the microhardness of the surface layer and it is 452–747 HV. It is known that the volume of iron boride fractions determines the degree of hardening of the steel surface. An increase in the plasma arc current leads to a decrease in the proportion of primary borides in the surface layer after alloying, and therefore leads to a decrease in microhardness. The alloyed layer has characteristic zones: hypereutectic, eutectic and hypoeutectic. An increase in current leads to a significant change in the microstructure of the surface layer and a decrease in the microhardness of the alloyed layer. The surface layer after plasma alloying with a current of 120 A has the highest microhardness (1265 HV). It has been established that it is possible to obtain a boride layer using the technology of plasma surface doping with boron. After processing, the alloyed layer is characterized by a heterogeneous structure and has high hardness.

Influence of Plasma Arc Current and Gas Flow on the Structural and Tribological Properties of TiN Coatings Obtained by Plasma Spraying

This study investigates the development of TiN-based coatings using plasma spraying technology, focusing on how plasma arc current and working gas flow rate affect the coatings’ structural-phase composition and mechanical–tribological properties. The research highlights the potential and effectiveness of plasma spraying for TiN coatings. Results from scanning electron microscopy and nanoindentation tests show that the TiN coatings have a dense microstructure with strong adhesion. Tribological testing demonstrated that coatings deposited at a 250 A arc current displayed the lowest coefficient of dry friction and the lowest porosity (2.13%) compared to those deposited at 350 A and 450 A arc currents, which exhibited higher porosity (up to 10.45%).

The preparation method of cells with boron nanoparticles to determine boron by direct current arc atomic emission spectrometry

An approach to quantify boron in cells after administration of boron nanoparticles (BNPs) stabilized in hydroxyethyl cellulose (HEC) was developed. In vitro experiments with human glioblastoma cells and BNPs stabilized in HEC were carried out. Cell samples with BNPs were dried on graphite powder under an infrared lamp and analyzed by direct current arc atomic emission spectrometry (DCA AES).

Hardening mechanism and thermal-solid coupling model of laminar plasma surface hardening of 65 Mn steel

In the present work, the laminar plasma surface hardening method is employed to enhance the service life of metal components fabricated from 65 Mn steel. The mechanical and wear behaviors of the laminar plasma surface hardened 65 Mn steel were analyzed. The martensite transition transformation of the temperature of the laminar plasma-hardened 65 ferrite Mn steel was determined by a thermal-solid coupling model. Based on the orthogonal experimental results, the optimal hardening parameters were confirmed. The scanning velocity, quenching distance and arc current are 130 mm/min, 50 mm and 120 A, respectively. The pearlites and ferrites are transformed into martensites in the hardened zone, while the ratio of martensite in the heat-affected zone decreases with the increase in the hardening depth. Compared to the untreated 65 Mn steel, the average hardness increases from 220 HV0.2 to 920 HV0.2 in the hardened zone and the corresponding absorbed power increases from 118.7 J to 175.5 J. At the same time, the average coefficient of friction (COF) decreases from 0.763 to 0.546, and the wear rate decreases from 5.39×10−6 mm3/(N·m) to 2.95×10−6 mm3/(N·m), indicating that the wear resistance of 65 Mn steel could be significantly improved by using laminar surface hardening. With the same hardening parameters, the depth and width of the hardened zone predicted by the thermal-solid coupling model are 1.85 mm and 11.20 mm, respectively, which are in accordance with the experimental results; depth is 1.83 mm and width is 11.15 mm. In addition, the predicted hardness distributions of the simulation model are in accordance with the experimental results. These results indicate that the simulation model could effectively predict the microstructure characteristics of 65 Mn steel.

Applications of H2-Enriched syngas and slag products from plastic wastes via novel plasma dual-stage-arc pyrolysis

Sustainable plastic waste management in the prevailing ‘new-normal’ post-pandemic scenario calls for calorific waste plastic up-cycling into high-end product recovery pathways. The present work employed a novel dual-stage arc plasma pyrolysis reactor to recover syngas and slag products from mixed plastics and Low-Density Polyethylene and Polyethylene Terephthalate (LDPE-PET) plastic waste feeds. Syngas product yield decreased while the solid slag yield increased with rising arc current, attaining 75% and 25% for mixed plastic waste feed and 59% and 41% for LDPE-PET wastes, respectively, at 200A arc current. The resultant syngas composition showed 83% and 77% H2 while 1.7% and 2.7% CO for mixed plastic waste-feed and LDPE-PET wastes, respectively, with no significant presence of CO2. Slag characterization studies revealed the presence of scattered pores on the slag surface, graphitic nanostructures due to scraped carbon depositions from electrode tips and the absence of aromatic groups due to complete conversion. High carbon content was observed in the slag due to the dissociation of lighter hydrocarbon and carbon dioxide on dual-arc exposure in two stages, underscoring the higher efficiency. For holistic integrated circular onsite ‘plastic waste-to-resource’ recovery-cum-application, electricity was generated from the resultant syngas and the slag was used for the manufacture of tiles in the community platform. Techno-economic evaluation of an up-scaled plasma pyrolysis facility shows the power recovery of 3.5 kWh/kg of waste plastic, with a net annual profit of $2800 and a payback period of 1.7 years. The findings of the present work suggest that the proposed integrated dual-arc plasma pyrolysis based plastic waste-to-resource recovery in circular-economy model has a viable outcome.

Hardfacing of GX40CrNiSi25-20 cast stainless steel with an austenitic manganese steel electrode

Abstract To enhance the wear and corrosion resistance of engineering components, various surface modification techniques have been devised. Among these, arc welding processes employing specialized electrodes offer relatively straightforward methods with low production costs for hardfacing applications. This paper focuses on the hardfacing process using pulsed current arc welding to reinforce cast austenitic steel structural components, aiming to prolong their lifespan. Typically, hardfacing coatings utilize Fe, Ni, and Co-based alloys. Among these, Fe-based alloys, such as manganese austenitic alloys employed in our experiments, are favored for their robust mechanical work hardening capacity, resulting in significant hardness enhancements (from 186–219 HV5 in the as-deposited layer to 468–492 HV5 after mechanical work hardening) under intense wear and impact conditions. The innovation of the hardfacing process developed in this study lies in utilizing a universal TIG source adapted for manual welding with a covered electrode in pulsed current mode. This hardfacing technique can be applied to both worn components in operation and new ones before being put into service, thereby ensuring long-term durability and reducing maintenance costs.

Generation of multiply charged metal ions in a high current short pulse vacuum arc

We have studied the plasma composition of a high current short pulse vacuum arc discharge with different cathode materials: lanthanum, gadolinium, lead, silver, and tin. We find that for optimal vacuum arc discharge parameters – arc current pulse duration about 2 μs and amplitude about 3 kA – the maximum ion charge state is 11+ and mean ion charge state from 7.8+ for tin to 9.6+ for lanthanum. The mean ion charge state for different materials depends on the discharge voltage and the energy required for ionization to maximum charge state. The cathode surface heats to a temperature of 700 °C–1100 °C in the course of the arc current pulse, depending on the cathode material, and the cathode surface of low melting point metals such as lead and tin melts to a depth of 5 μm and 10 μm, respectively. Surface melting does not lead to change in plasma ion composition, since the ion flux from the cathode considerably exceeds the evaporated atom flux.

A grey relational analysis of the micro arc oxidation process parameters and their effects on Ti-6Al-7Nb coating performance and corrosion resistance for biomedical uses

Abstract In current investigation micro arc oxidation of Ti6Al7Nb alloy was done to improve its surface properties and corrosion resistance. Mixture of Na2SiO3, Na3PO412H2O and KOH is used as electrolyte. MAO treated Ti6Al7Nb specimens were examined using x-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) to examine their morphology and phase composition. It was observed that electrolyte composition is simultaneously included in the growing oxide layer during MAO process. From electrochemical study it was found that corrosion resistance of the Ti6Al7Nb increases during EIS testing in 0.9% NaCl solution. It was found that frequency, duty cycle, current and processing time effect the surface roughness, thickness, hardness and corrosion resistance of coating. Out of above mention parameters frequency and duty cycle has major impact on performance parameters. The objective of current investigation is to find out effects MAO process parameters on coating performance parameters such as coating thickness, hardness, surface roughness and corrosion resistance. At duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min, highest coating thickness 32.96 μm and surface roughness 3.3680 μm was obtained. Process parameters have the influence on pore size, biggest average pore size 3.8519 μm was obtained at duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min. Grey relational analysis is done to determine which process variable has the most influence on performance parameters. From grey relational analysis technique, it was observed that duty cycle 50%, frequency 500 Hz, current 300 mA, and processing time 7.5 min are ideal process parameters for higher coating thickness, hardness, surface roughness and better corrosion resistance. From grey relation analysis it was also found that frequency has most significant impact on performance parameters after that duty cycle, then current and at last processing time.