Electrochemical Honing Research Articles

CONVERGENCE TECHNOLOGY FOR VEHICLE PART SURFACE FINISHING

The subject of this research is convergence technology for the surface finishing of vehicle parts. A literature review has been conducted to carry out a comparative analysis of existing methods for the surface finishing of parts used in the manufacturing of aircraft, hydraulic and pneumatic devices, and other vehicles. Prospects are shown for further research on methods with the aim of creating a complex technology (i.e., convergence) that combines information technologies; nanotechnologies; and thermochemical, electrochemical, and mechanical processing methods. A method is proposed for selecting and combining surface finishing methods according to a five-point expert assessment, which allows the batch processing of vehicle parts. Based on this method, the concept of convergence technology for the surface finishing of vehicle parts is proposed, which includes the impulse thermal energy method, honing, superfinishing, and electrochemical processing. An expanded process is presented for manufacturing parts with high-precision, low-roughness surfaces and a specified microrelief by using electrochemical superfinishing and electrochemical honing. A scheme of the concentration (focusing) of the current flow during electrochemical superfinishing due to the movement of the electrode relative to the part surface is proposed, which enables the effect of surface polishing and the removal of oxidation products. Convergence technology for the surface finishing of vehicle parts will provide parts’ geometric dimensions with micro- and nano-precision and allow the precision machining of small-diameter holes and complex profiles, increased machining accuracy (up to 0.001 microns), the possibility of batch processing, and the possibility of process automation.

Study of Selective Parameters Influencing Surface Roughness and Metal Removal Rate of Internal Cylinders Produced By ECH (Dept.M)

Electrochemical Honing process (ECH) is a modification of conventional honing techniques whereby material is removed from electrically conductive workpieces through a combination of anodic dissolution and mechanical abrasion. Eighty percent, or more, of the material removal occurs through electrolytic action. ECH is one of the non-equilibrium processes and is a technique, which in spite of being used in some industrial plants especially to smoothen surfaces, is still not fully described due to the variety of the factors affecting the process. More information about the process is required, especially the effects of the working parameters on the produced surface roughness. This paper reports experimental findings on the effect of important process parameters such as workpiece material, time, applied current, initial working gap, rotational speed, electrolyte type and concentration and tool tip shapes on surface quality and metal removal rate (MRR). A special designed honing test rig , which is developed at the laboratory, was used. The surface roughness and (MRR) are measured. The experimental results are a useful guideline for the user for proper selection of conditions for obtaining a good surface quality.

An Analysis on the Parametric Optimization of Electrochemical Honing Process

Electrochemical honing (ECH) is a nontraditional machining process hybridizing the conjoint benefits of electrochemical machining (ECM) and mechanical honing actions. In this process, maximum amount of material is removed through anodic dissolution, followed by mechanical abrasion. In present day manufacturing industries, it has found wide ranging applications, mainly in finishing of varieties of gears, due to its various advantages, like increased material removal rate, long tool life, burr-free operation, achievement of higher surface finish and dimensional accuracy, generation of no residual stress, reduced noise, less material damage, etc. In order to achieve maximum machining capability from this process, it is always recommended to set its various input parameters at their optimal operating levels. In this paper, four powerful metaheuristic algorithms, i.e. firefly algorithm, differential evolution (DE) algorithm, cuckoo search (CS) algorithm and teaching–learning-based optimization (TLBO) algorithm are applied for single as well as multi-objective optimization of pulsed-ECH (PECH) and ECH processes. It is observed that TLBO algorithm supersedes other techniques in optimizing the two ECH processes with respect to the value of the derived optimal solution, consistency of the solutions and computational speed.

Challenges and Opportunities in ECH of Gears

Electrochemical honing (ECH) is an encouraging technique of gear finishing because of its micro-removal characteristic. In ECH, material removes by combined effect of anodic dissolution and mechanical abrasion. It is a hybrid micro-finishing process. ECH is a productive technique of gear finishing with high accuracy and long tool life. However, the lack of comprehensive research and complex setup design prevents it from being commercialized. This paper discusses the emphatic features of electrochemical honing of gears; its prospective features and capabilities. A comparative study is executed to explore the improvement in process capability and advantages of it. The shortcomings of the process are also discussed. Some guidelines are also mentioned for future research. It helps research community to mature this process further.

Performance of different abrasive tools in electrochemical honing of coated surfaces

This paper highlights on the honing characteristics of various abrasive tool materials during the precision finishing of EN52 coated surface of the engine valve face using electrochemical honing ECH process. The investigation on various abrasive tool materials in ECH is first proposed, and it may help to enhance the processing of sophistic surfaces. It is a new technique, which in spite of being used in some industrial plants, in particular to smooth surfaces and is still not fully described due to the variety of the factors affecting the process. More information about the process is required, especially the honing related parameters, such as abrasive tool pressure, abrasive material, and abrasive size. Special shaped honing tools were designed and fabricated to study the present aspects. Two different types of abrasive tool material (Al2O3 and NiCr) for honing operation were used while ECH of EN52 work surface. The results of the experiments are finally furnished with the aim to generalise a useful guideline for the user to enable proper selection of conditions for obtaining good surface quality.

Performance of different abrasive tools in electrochemical honing of coated surfaces

Performance of different abrasive tools in electrochemical honing of coated surfaces

COMBINATION OF DIAMOND-ELECTROCHEMICAL HONING AND GALVANIC CHROME-PLATING

For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version).ABSTRACT Electrochemical methods have found their greatest usefulness in the dimensional machining of surfaces of machine parts, based on complex processes of metal dissolution. The authors study the results of bench tribological tests of the results of application of the combined method of diamond electrochemical honing and galvanic chroming, creating high-strength surface layers, that showed the measure of intensity of wear, deviation from the optimum regimes, the causes and nature of emergence of coating defects. To fulfill the test conditions, appropriate equipment, technological equipment, tools were used, and an appropriate type of electrolyte medium was provided. The structure of the created equipment, in particular, included modernized vertical honing semi-automatic machines and mechanical devices. Based on the test results, the possibility of combining two methods of electrochemical metal surface treatment subject to high tribological load was confirmed. Keywords: machine parts, tribology, combined treatment, electrochemical processing, diamond electrochemical honing, galvanic chroming, wear, dimensional machining.

Parameter optimization of ECH process for surface finish on ASTM-35 cast iron

This paper presents an experimental parameter optimization of electrochemical honing process (ECH) on the surface finish generation capability on cast iron of ASTM 35 with Brinell Hardness Hb 212. Taguchi orthogonal array of L9 experiment is used for optimization. Results from the main effect plot, regression analysis, correlation analysis, and interaction plots for the means indicate that best surface finish is obtained where the electric voltage is 15 V, electrolyte concentration is 20%, electrolyte pressure is 0.667 Mpa, and motor rotational speed is 60 rpm. However, significant variation is seen in the control of electric voltage as compared to the other three. Higher signal-to-noise ratio is observed on electric voltage followed by electrolyte concentration and electrolyte pressure signifying electric voltage is the determining factor. From standard deviation analysis, electrolyte pressure and electrolyte concentration are found to need close attention for better surface roughness along with electric voltage. The interaction plot for the three factors also indicates that electric voltage at highest level is more significant than the other factors. However, it is noted that the interaction of the electric voltage, electrolyte concentration, and electrolyte pressure significantly determines the effectiveness of the ECH process. Meanwhile, the level of control between electrolyte pressure and electrolyte concentration needs careful attention as the two factors work against each other.

Study on nanofinishing of SS304 flat surfaces using electrochemical honing process

Surface integrity of the flat surfaces has become an inevitable part to perform specific functions. In some cases, a nano level surface finish and excellent geometrical accuracy are required in their applications. In this work, an attempt has been made to meet the challenges of the finishing of flat surface (2D) using electrochemical honing (ECH) process. A series of experimental runs were conducted on SS304 flat surfaces to analyse the effect of process parameters on the output measures. Results show that finishing time, electrolyte concentration, and voltage which had a significant effect on the output measures in terms of percentage improvement in average surface roughness (PIRa) and percentage improvement in flatness (PIF). The developed empirical model shows good agreement with the confirmation experiments. The SEM images showed that the processed surface gives the glazed appearance and zero tool feed marks.

Critical review of electrochemical honing: sustainable and alternative gear finishing process. Part 2: effects of various process parameters on surface characteristics and material removal rate

Part 1 of this review discussed conventional gear surface finishing processes and their advantages and limitations, and introduced the electrochemical honing (ECH) process (and its extension of pulsed electrochemical honing (PECH)), to improve the surface characteristics of different types of gears, working principles, mechanism of material removal and equipment details. Part 2 gives a review of past work, and discusses effects of various process parameters on surface characteristics and finishing productivity (i.e. material removal rate), advantages and limitations, and its other applications. The objective of this review paper is to present ECH/PECH as one emerging alternative, economical, productive and sustainable gear finishing process.

Critical review of electrochemical honing (ECH): sustainable and alternative gear finishing process. Part 1: conventional processes and introduction to ECH

Surface characteristics of gears affect the various performance characteristics of the gears such as load carrying capacity, service life, operating performance, wear characteristics, transmission characteristics and noise generation characteristics. Surface characteristics of a gear have two major components namely (i) surface quality which includes surface finish, micro-geometry (i.e. form and location errors), tooth flank topology and wear characteristics; and (ii) surface integrity aspects which includes microstructure, microhardness and residual stresses. This paper discusses here in Part 1 conventional gear surface finishing processes and their advantages and limitations, and introduces the electrochemical honing (ECH) process to improve the surface characteristics of different types of gears, working principles, mechanism of material removal and equipment details. Part 2 will give a review of past work, and discuss effects of various process parameters on surface characteristics and finishing productivity (i.e. material removal rate), advantages and limitations, and its other applications. This review paper aims to establish ECH as one emerging alternative, economical, productive and sustainable gear finishing process.

Modeling and experimental validation of volumetric material removal rate and surface roughness depth of straight bevel gears in pulsed-ECH process

This paper describes development of theoretical models of volumetric material removal rate (MRR) and surface roughness depth (Rz) of straight bevel gears finished by pulse electrochemical honing (PECH) process in terms of the most influencing parameters namely applied voltage, pulse-on time, pulse-off time, finishing time, inter-electrode gap, electrolyte conductivity and workpiece gear rotary speed. Equations for computing flank surface area of gear tooth flank surfaces in terms geometric parameters of involute profile of straight bevel gears were also developed. The developed models were validated by conducting twelve experiments using one-factor-at-a-time approach and varying applied voltage, pulse-on time and pulse-off time each at four levels. Values and trends of variation of volumetric MRR and surface roughness depth predicted by the proposed models have shown very close agreement with corresponding experimental values and their trends. Minimum prediction errors for the proposed models were found to be −3.3% and 1% for volumetric MRR and surface roughness depth respectively. Models and validation results have also revealed the existence of optimum ranges of voltage, pulse-on time and pulse-off time to optimize volumetric MRR and depth of surface roughness. Analysis of different aspects of surface quality (i.e. surface finish, material ratio curve, micro-geometry, tooth flank topology) and surface integrity (i.e. microstructure and micro-hardness) of the best-finished gear have shown considerable improvements in them.

Optimization of Key Process Parameters on Electro Chemical Honing (ECH) of External Cylindrical Surfaces of Titanium alloy Ti 6Al 4V

Electrochemical honing (ECH) is one of the most advanced precision machining process used for finishing of cylinders and gears, based on the combination of electrochemical machining process having high material removal rate and generation of controlled smooth surface finish by conventional honing process. ECH is a well known process for offering an excellent work surface quality on material of any hardness as long as it is electrically conductive. The process made ECH as an ideal choice for improving the surface quality of critical components made of hard and tough materials like Inconel, Incolay, Titanium & Nickel alloys etc. It also describes the design and fabrication of an indigenously developed tooling setup for ECH of an external cylindrical components. Titanium alloy (Ti 6Al 4V) and EN8 Steels are used as work piece material for carrying out the experimentations. Various key process parameters are discussed for better surface finish Ra and for more material removal and their effect on ECH process is discussed for Ti alloy. It compares and evaluates the percentage improvements in surface roughness values, with respect to processing time (PT) and distinguishes the surface characteristics of micro and macro level. Electro chemical honing process has been employed to achieve highest material removal rate with the best surface qualities.

Study on ultrasonic-assisted electrochemical honing of bevel gears

Electrochemical honing of gears is a productive, high-accuracy, micro-finishing and long tool life gear finishing process in which material is removed by combined action of electrolytic dissolution and mechanical scrubbing action. The use of ultrasonic-assisted electrochemical honing of gears is first proposed, and it may help to enhance the process performances of the classical electrochemical honing process by scrubbing the complete surface of the gear tooth. In this technique, the honing gear is attached on the ultrasonic vibrator to provide the ultrasonic vibrations on the workpiece surface. The focus is on an optimization of the process parameters of ultrasonic-assisted electrochemical honing of bevel gear made of AISI 1040 carbon steel. The result of experiments reveals that the applied high ultrasonic frequency (kHz) on the workpiece has the maximum influence on the process performance. The maximum percentage improvement in average and maximum surface roughness using ultrasonic-assisted electrochemical honing of bevel gear is 91.04 and 71.98, respectively. The results confirm that the ultrasonic-assisted electrochemical honing can produce a better tooth surface roughness than the electrochemical honing. This will improve bevel gear efficiency and reliability in operation.

Effect of applied voltage and electrolyte parameters on pitch, runout, flank topology, and finishing productivity of the straight bevel gears in PECH process

ABSTRACTThis paper describes improvements in the considered parameters of micro-geometry: flank surface topology and finishing productivity of 20MnCr5 alloy steel straight bevel gears through their finishing by pulsed electrochemical honing (PECH) process. Effects of three most important parameters of PECH process, namely applied voltage, electrolyte composition, and electrolyte concentration were investigated to identify their optimum values. Pre-identified values of other PECH parameters and an aqueous mixture of NaCl and NaNO3 as an electrolyte were used in the present work. Errors in pitch (i.e., single pitch error, adjacent pitch error, and cumulative pitch error) and runout were used to evaluate micro-geometry of the straight bevel gears while volumetric material removal rate was used to judge the finishing productivity of the PECH process. Topology of the gear tooth flank surface and microstructure of the best-finished bevel gears were also studied. The results revealed considerable improvements in the micro-geometry, flank surface topology, and microstructure of the bevel gears finished by PECH. Applied voltage of 8 V, electrolyte composition of 75 wt.% NaCl + 25 wt.% NaNO3, and electrolyte concentration of 7.5 wt.% were identified as the optimum values to achieve simultaneous improvement in all the considered responses.

Investigations on surface quality, surface integrity and specific energy consumption in finishing of straight bevel gears by PECH process

Applications of electrochemical finishing (ECF) and its hybridization with the other mechanical processes are attracting the interest for finishing various engineering components due to their flexible behavior. Pulse electrochemical honing (PECH) is a hybrid finishing process which provides benefits of pulsed ECF and mechanical honing processes simultaneously to improve the surface quality and surface integrity of the workpiece components. The present study is aimed at studying the effects of the three most important PECH parameters namely applied voltage, electrolyte composition, and electrolyte concentration on the aspects of surface quality (i.e., surface roughness, waviness, material ratio curve), of surface integrity (i.e., wear indicators, microhardness, microstructure, and residual stresses), and of finishing productivity (i.e., material removal rate) of the straight bevel gears made of alloy steel (20MnCr5) by the PECH process. An aqueous mixture of non-passivating electrolyte (i.e., NaCl) and passivating electrolyte NaNO3 was used as electrolyte. The three input parameters were varied at three levels to identify their optimum combination using preidentified optimum values of other process parameters. The identified optimum values are 75 % NaCl + 25 % NaNO3 as electrolyte composition, 7.5 % as electrolyte concentration, and 8 V as applied voltage while finishing the bevel gears for an optimum duration of 6 min. Results have shown significant improvement in surface roughness (i.e., the average surface roughness value reduced from 2.84 to 1.03 μm; the maximum surface roughness value decreased from 24.59 to 6.06 μm; depth of roughness reduced from 13.51 to 5.42 μm) and surface waviness (i.e., average waviness reduced from 5.04 to 1.58 μm; maximum waviness reduced from 30.17 to 5.52 μm). Analysis of microstructure, residual stresses, material ratio curve, wear indicators, and microhardness of the PECH-finished gears also showed significant improvement in them compared to an unfinished gear. Comparative analysis of energy consumption in PECH and ECH processes found that PECH consumes 25 % less energy than the ECH process does for achieving the same level of finishing. The present work proves that PECH is a superior, productive, and more energy-efficient process compared to the conventional gear finishing processes and ECH process.

Application of MCDM-Based TOPSIS Method for the Optimization of Multi Quality Characteristics of Modern Manufacturing Processes

Optimization of non-conventional machining (NCM) processes viz. AJM, AWJM, EDM, WEDM, ECM, ECMM, LBM, PAC, etc. has always been an open research area for researchers. In recent manufacturing environment, almost all the NCM processes consist of a number of input and output to be considered together. The purpose of the present article is to highlight the application of a multi-criteria decision making (MCDM) based method called Technique of Order Preference by Similarity of Ideal Solution (TOPSIS) in optimization of some modern manufacturing processes (MMPs). In the present paper, seven different MMPs namely Electro Chemical Honing (ECH), Abrasive Water Jet Machining (AWJM), Abrasive Jet Machining (AJM), Laser Beam Machining (LBM), Plasma Arc Cutting (PAC), Laser Cutting (LC) and Electric Discharge Machining (EDM) were exemplified. The multiple outcomes of all the illustrated MMPs have been optimized simultaneously by using TOPSIS method. It is a simple, systematic, and logical technique which can be employed to obtain the best parametric combination of cutting parameters. It was observed that the results attained by using TOPSIS method were almost tie with those derived by past researchers. This proves the applicability and adaptability of the TOPSIS method while solving different MCDM-based problems in a real manufacturing system.

Remanufacturing of functional surfaces using developed ECH machine

Determination of optimal input parameters is one of the important elements in any process planning of the metal parts. The aim of the study is to investigate the optimization of processing parameters in order to enhance the surface micro-finish and geometrical accuracy of the recovered functional surfaces made of SS316 material using a newly developed electrochemical honing (ECH) machine. ECH is a prominent hybrid machining process, which is widely used for precision finishing of intricate shapes and hard materials with an efficient and effective manner. In this work, discarded functional surface of the cylindrical shafts is recovered using twin wire arc (TWA) technique and its surface topography was studied using developed micro-finish machine. The results show that the ECH of recovered surfaces gives a glazed texture and produce an average surface roughness of 0.347 μm with the processing time of 90 s. The monitored outputs such as surface roughness (average, Ra and maximum, Rt) and geometrical accuracy such as out-of-roundness (OR) was measured during the investigation to optimized the process performance characteristics.

Influence of ultrasonic vibrations on process performance of electrochemical honing

Electrochemical honing (ECH) is a novel variant of hybrid machining processes (HMPs). The key feature is that the distinct coupling of electrochemical machining (ECM) and honing provide a controlled functional surface generation and faster material removal rate in a single operation. In the present study, the influence of ultrasonic vibrations on process performance of ECH of bevel gears made of EN8 is investigated. An analysis of the process has been presented with suitable illustrations. Ultrasonic frequency and processing time were considered as the input variables while improvement in surface finish, material removal and geometrical accuracies were considered as the monitored output. The effectiveness of the process was investigated through experimental trials by conducting a comparison study between classical ECH and ultrasonic vibration-assisted ECH (UECH). The results confirm that improvements in surface roughness and martial removal rate are significantly higher than those obtained with classical ECH. The study further reveals that the scrubbing of the oxide layer is easier to be achieved and surface quality is obviously improved due to ultrasonic vibrations. The experimental results demonstrate that UECH gives 18.36 % improvement in average roughness, 9.31 % improvement in maximum roughness and 20 % improvement in material removal rate as compared with ECH.

Study on electrolyte composition for surface improvement during ECH of turned titanium alloy

Electrochemical honing (ECH) is an ideal choice to machine hard passive materials such as titanium alloys for aerospace applications. Researchers have found electrochemical machining of titanium alloys as difficult because of huge amount of oxide film formation. The ECH process with conventional honing tool scrubs the passivating electrolytic metal oxide microfilm from higher work-profile area to allow clean surface for electrolysis. The selection and composition of electrolytes are key input factors to achieve better results during ECH. The present study focuses on the effect of NaCl and KBr mixture electrolyte on surface finish of turned titanium alloy Ti-6Al-4V. Experimental studies have been conducted with varying percentage composition of NaCl and KBr. It is found that in a 10% mixture electrolyte, 75% NaCl with 25% KBr is optimum for achieving surface finish in nano-scale with improvement in average surface roughness by 86% and maximum height of the profile decrease by 56%.