Combination Levels Of Machining Parameters Research Articles

Investigation of a novel ultrasonically aided electrochemical magnetic abrasive machining process for SS 316L

Many present day applications require machining and finishing of complex-shaped and tough to machine materials with precision and accuracy by conventional or non-conventional machining and polishing processes. Ultrasonically aided electrochemical magnetic abrasive machining (UAEMAM) process is a novel non-conventional machining technique which can machine and finish the product for better surface quality. In present research work, the development and performance evaluation of UAEMAM process for machining of SS 316L is reported. The UAEMAM process is optimised using response surface methodology (RSM) based on central composite design (CCD) and grey relational analysis. The main machining variables of UAEMAM such as work piece rotational speed, working gap, concentration of NaNO3, percentage of abrasives by weight and pulse on time were considered to determine percentage improvement in surface finish (PISF) and material removal rate (MRR). The significant machining factors and the best combination levels of machining parameters associated with PISF and MRR were determined. The present work shows complete elimination of oxide layer from work piece surface, subsequently increasing the PISF value to 84.73 which is 2.73% higher than value achieved by previous studies employed. The benefits of ultrasonic aided electrochemical magnetic abrasive machining were also confirmed from the micrograph observations of the surface. Experimental results show that UAEMAM process is effective for machining and polishing components for better surface finish.

Multi-Performance Optimization in Electrical Discharge Machining of Al2O3 Ceramics Using Taguchi Base AHP Weighted TOPSIS Method

The main application of electrical discharge machining in ceramic processing is limited to conductive ceramics. However, the most commonly used non-conductive potteries in modern industry, such as aluminum oxide (Al2O3), also reveal the limitations of choosing a suitable process. In this study, Taguchi based TOPSIS coupled with AHP weight method to optimize the machining parameters of EDM on Al2O3 leads to better multi-performance. The results showed that the technique is suitable for tackling multi-performance machining parameter optimization. The adhesive foil had a significant impact on material removal rate, electrode wear rate, and surface roughness, according to the findings. In addition, the response graph of relative closeness is used to determine the optimal combination levels of machining parameters. A confirmation test revealed a good agreement between predicted and experimental preference values at an optimum combination of the input parameters. The suggested experimental and statistical technique is a simple, practical, and reliable methodology for optimizing EDM process parameters on Al2O3 ceramics. This approach might be utilized to optimize and improve additional process parameters in the future.

Machining Performances of Electrical Discharge Machining Combined with Abrasive Jet Machining

The aim of this study is to investigate the machining characteristics of a developed hybrid process of electrical discharge machining (EDM) in gas with abrasive jet machining (AJM). The experiments with regard to parameter optimization were designed with an L18 orthogonal array based on Taguchi method. The main process parameters such as machining polarity, peak current, pulse duration, gas pressure, grain size, and servo reference voltage were chosen to determine their effects on machining performance relating to material removal rate (MRR), electrode wear rate (EWR) and surface roughness (SR) for SKD 61 tool steel. The experimental response values were transferred to signal-to-noise (S/N) ratios, and then the significant machining parameters associated with the machining performance were examined by analysis of variance (ANOVA). The optimal combination levels of the machining parameters were also obtained from the response plots of S/N ratios. The experimental results show that the significant machining parameters affecting the MRR were machining polarity, peak current, and pulse duration; peak current was the significant parameter with relation to the EWR; in addition, the peak current, pulse duration, as well as gas pressure were the significant in regard to the SR. Moreover, The S/N ratios were improved 9.51dB, 3.44dB and 4.52dB at the optimal combination levels of machining parameters from the confirmation experiments for MRR, EWR and SR, respectively. Consequently, the developed hybrid process of EDM in gas and AJM could enhance the machining efficiency to fit the requirements of modern manufacturing applications.

An experimental investigation on machining parameters of AISI D2 steel using WEDM

The performance of the wire electrodischarge machining (WEDM) machining process largely depends upon the selection of the appropriate machining variables. Optimization is one of the techniques used in manufacturing sectors to arrive for the best manufacturing conditions, which are essential for industries toward manufacturing of quality products at lowest cost. As there are many process variables involved in the WEDM machining process, it is difficult to choose a proper combination of these process variables in order to maximize material removal rate and to minimize tool wear and surface roughness. The objective of the this work is to investigate the effects of process variables like pulse on time, pulse off time, peak current, servo voltage, and wire feed on material removal rate (MRR), surface roughness (SR), gap voltage, gap current, and cutting rate in the WEDM machining process. The experiment has been done using Taguchi’s orthogonal array L27 (35). Each experiment was conducted under different conditions of input parameters and statistically evaluated the experimental data by analysis of variance (ANOVA) using MINITAB and Design Expert tools. The present work also aims to develop mathematical models for correlating the inter-relationships of various WEDM machining parameters and performance parameters of machining on AISI D2 steel material using response surface methodology (RSM).The significant machining parameters and the optimal combination levels of machining parameters associated with performance parameters were also drawn. The observed optimal process parameter settings based on composite desirability (61.4 %) are pulse on time 112.66 μs, pulse off time 45 μs, spark gap voltage 46.95 V, wire feed 2 mm/min, peak current of 99.99 A for achieving maximum MRR, gap current, gap voltage, cutting rate, and minimum SR; finally, the results were experimentally verified.

Optimal Machining Parameters of EDM in Gas Based on Response Surface Methodology

This paper aims to establish an effective mathematical model with relation to electrical discharge machining (EDM) in gas based on response surface methodology (RSM). Moreover, the optimal combination levels of machining parameters for material removal rate (MRR) and surface roughness (SR) were also explored. The experimental tasks were implemented by a specific design of experimental method named central composite design (CCD) method based on RSM to develop quadratic regression mathematical model. The significant parameters and their interactions were examined by analysis of variance (ANOVA) to evaluate the importance on MRR and SR. The essential parameters of EDM in gas such as peak current (I_p), pulse duration (T_p), air pressure (G_P) and servo reference voltage (S_v) were chosen to investigate the effects on MRR and SR. From the analysis results, the optimal set of parameter setting levels were 12 A peak current (I_p), 750 μs pulse duration (T_p), 5 kg/cm<sup>2<sup> gas pressure (G_P) and 34 V servo reference voltage (S_v), and the optimization of MRR and SR were 1.99 mm<sup>3<sup> and 2.43μm as the machining parameters were set at the optimal levels.

Optimization of Multiple Performances for EDM in Gas Media Using Grey Relational Analysis

The aim of this investigation is to optimize the multiple performance characteristics of electrical discharge machining (EDM) for SKD 61 tool steel in gas media using grey relational analysis. The three most important machining characteristics namely material removal rate (MRR), electrode wear rate (EWR), and surface roughness (SR) were considered as the measures of the performance characteristics. A series of experiments were conducted according to an L18 orthogonal array based on the Taguchi experimental design method. The observed data obtained from the experiments were evaluated to determine the optimization of machining parameters correlated with multiple performance characteristics through grey relational analysis. Moreover, analysis of variance (ANOVA) was conducted to explore the significant machining parameters crucially affecting the multiple performance characteristics. In addition, the optimal combination levels of machining parameters were also determined from the response graph of grey relational grades for each level of machining parameter.

Machining Performance Optimization in End ED Milling and Mechanical Grinding Compound Process

Silicon carbide (SiC) ceramic has been widely used in modern industry for its excellent physical and mechanical properties. However, SiC ceramic is difficult to machine owing to its high hardness and brittleness. This article presents a novel compound process that integrates end electric discharge (ED) milling and mechanical grinding to machine SiC ceramic. The process is able to effectively machine a large surface area on SiC ceramic with a good surface quality. The effect of tool polarity on the machining characteristics such as the material removal rate (MRR), tool wear ratio (TWR), and surface roughness (SR) has been explored. The effects of pulse on-time, pulse off-time, discharge current and open voltage on MRR, TWR, and SR have been investigated with Taguchi experimental design. The experimental data are statistically evaluated by analysis of variance and stepwise regression. The significant machining parameters, the optimal combination levels of machining parameters, and the mathematical models associated with the machining characteristics are obtained. The confirmation experiment results confirm the validity of the used Taguchi method for enhancing the machining performance and optimizing the machining parameters.

Response Surface Analysis of EDMED Surfaces of AISI D2 Steel

In this study, the effects of the machining parameters in electrical-discharge machining (EDM) on the machining characteristics of AISI D2 steel using copper electrodes were investigated. The response functions considered material removal rate (MRR) and Surface Roughness (Ra),while machining variables are pulse current, pulse on time, pause time and gap voltage. A Response surface methodology was used to reduce the total number of experiments. Empirical models correlating process variables and their interactions with the said response functions have been established. The significant parameters that critically influenced the machining characteristics were examined, and the optimal combination levels of machining parameters for material removal rate, and surface roughness were determined. The models developed reveal that pulse current is the most significant machining parameter on the response functions followed by voltage and pulse off time for MRR. However for, for Ra also pulse current is most significant followed by pulse on time and discharge voltage the respectively. The model sufficiency is very satisfactory as the coefficientR2of is determination (R2) is found to these be greater than 98 %. These models can be used for selecting the values of process variables to get the desired

Improvement of wire electrical discharge machining efficiency in machining polycrystalline silicon with auxiliary-pulse voltage supply

This study proposes a novel pulse voltage configuration, auxiliary-pulse voltage, for wire electrical discharge machining (WEDM) of polycrystalline silicon (polysilicon) used in solar cell production. It is developed with the objectives of reducing material waste due to the large kerf loss as well as achieving greater efficiency and better quality compared with conventional machining approaches. Experimental results show that compared with conventional-pulse voltage supply, the auxiliary-pulse voltage mode can avoid delay in electrical discharge during pulse-on time. Enhanced frequency of effective discharge for machining would increase machining speed, which would in turn reduce machining groove width, and obtain better surface roughness. In addition, parameters of significant influence on machining characteristics were examined with the Taguchi method, and the optimal combination levels of machining parameters were determined. In sum, our findings reveal that WEDM with auxiliary-pulse voltage supply is an effective approach to machining polysilicon with good quality and high efficiency achieved.

ELECTRIC DISCHARGE MILLING AND MECHANICAL GRINDING COMPOUND MACHINING OF SILICON CARBIDE CERAMIC

Silicon carbide (SiC) ceramics have been widely used in modern industry. However, the manufacture of SiC ceramics is not an efficient process. This paper proposes a new technology of machining SiC ceramics with electrical discharge milling and mechanical grinding compound method. The compound process employs the pulse generator used in electrical discharge machining, and uses a water-based emulsion as the machining fluid. It is able to effectively machine a large surface area on SiC ceramics with a good surface quality. In this paper, the effects of pulse duration, pulse interval, peak voltage, peak current and feed rate of the workpiece on the process performance parameters, such as material removal rate, relative electrode wear ratio and surface roughness, have been investigated. A L25 orthogonal array based on Taguchi method is adopted, and the experimental data are statistically evaluated by analysis of variance and stepwise regression. The significant machining parameters, the optimal combination levels of machining parameters, and the mathematical models associated with the process performance are obtained. In addition, the workpiece surface microstructure is examined with a scanning electron microscope and an energy dispersive spectrometer.

Optimization of Thermal Friction Drilling Using Grey Relational Analysis

The main purpose of this research is to study the optimal machining parameters for a novel process of thermal friction drilling on SUS 304 stainless steel. The experiments were conducted according to an L9 orthogonal array based on Taguchi experimental designs method, and the multiple performance characteristics correlated with surface roughness (SR) and bush length (BL) was investigated by grey relational analysis systematically and comprehensively. Moreover, the significant machining parameters that most intensively affected the multiple performance characteristic and the optimal combination levels of machining parameters associated with the thermal friction drilling on SUS 304 stainless steel were determined through the analysis of variance (ANOVA) and the response graph of grey relational grade. The main machining parameters of the thermal friction drilling such as friction angle, friction contact area ratio, feed rate, and drilling speed were selected to evaluate the effects on SR and BL. The experimental results show that the thermal friction drilling revealed beneficial effects on SR and BL for drilling processes. Moreover, the optimal machining parameters for multiple performance characteristics associated with SR and BL were attained. The developed thermal friction drilling avoids serious tool wears, enhances the surface quality of the machined hole, and prolongs the tool life significantly.

Optimization of electrodischarge machining parameters on ZrO2 ceramic using the Taguchi method

The purpose of the present investigation was to optimize the electrodischarge machining (EDM) parameters for machining ZrO2 ceramic. During the EDM process, the surface of the electrically non-conductive ceramic was covered with adhesive conductive copper and aluminium foils to attain the threshold of electrical conductivity for the EDM process. The machining characteristics associated with the EDM process such as material removal rate (MRR), electrode wear rate (EWR), and surface roughness (SR) were explored through the experimental study according to an L18 orthogonal array based on the Taguchi experimental design method. Analysis of variance was conducted to examine the significant machining parameters affecting the machining characteristics. The experimental results show that peak current and pulse duration significantly affected MRR and SR, and the adhesive conductive material was the significant parameter correlated with EWR. In addition, the optimal combination levels of machining parameters were also determined from the response graph of signal-to-noise ratios for each level of machining parameters. The aim of the study was to establish a feasible process and optimize the parameter levels for processing electrically non-conductive ceramics through EDM. A practical and convenient process for shaping electrically non-conductive ceramics was developed in the present work with the features of high efficiency, high precision, and excellent surface integrity.

Optimization of machining parameters in magnetic force assisted EDM based on Taguchi method

A versatile process of electrical discharge machining (EDM) using magnetic force assisted standard EDM machine has been developed. The effects of magnetic force on EDM machining characteristics were explored. Moreover, this work adopted an L18 orthogonal array based on Taguchi method to conduct a series of experiments, and statistically evaluated the experimental data by analysis of variance (ANOVA). The main machining parameters such as machining polarity ( P), peak current ( I p), pulse duration ( τ p), high-voltage auxiliary current ( I H), no-load voltage ( V) and servo reference voltage ( S v) were chosen to determine the EDM machining characteristics such as material removal rate (MRR) and surface roughness (SR). The benefits of magnetic force assisted EDM were confirmed from the analysis of discharge waveforms and from the micrograph observation of surface integrity. The experimental results show that the magnetic force assisted EDM has a higher MRR, a lower relative electrode wear ratio (REWR), and a smaller SR as compared with standard EDM. In addition, the significant machining parameters, and the optimal combination levels of machining parameters associated with MRR as well as SR were also drawn. Moreover, the contribution for expelling machining debris using the magnetic force assisted EDM would be proven to attain a high efficiency and high quality of surface integrity to meet the demand of modern industrial applications.

Optimization of machining parameters using magnetic-force-assisted EDM based on gray relational analysis

This work developed a novel process of magnetic-force-assisted electrical discharge machining (EDM) and conducted an experimental investigation to optimize the machining parameters associated with multiple performance characteristics using gray relational analysis. The main machining parameters such as machining polarity (P), peak current (IP), pulse duration (τP), high-voltage auxiliary current (IH), no-load voltage (V), and servo reference voltage (SV) were selected to explore the effects of multiple performance characteristics on the material removal rate, electrode wear rate, and surface roughness. The experiments were conducted according to an orthogonal array L18 based on Taguchi method, and the significant process parameters that affected the multiple performance characteristics of magnetic-force-assisted EDM were also determined form the analysis of variance. Moreover, the optimal combination levels of machining parameters were also determined from the response graph and then verified experimentally. The multiple performance characteristics of the magnetic-force-assisted EDM were improved, and the EDM technique with high efficiency, high precision, and high-quality surface were established to meet the demand of modern industrial applications.

Machining Characteristics and Optimization of Machining Parameters of SKH 57 High-Speed Steel Using Electrical-Discharge Machining Based on Taguchi Method

The effects of the machining parameters in electrical-discharge machining (EDM) on the machining characteristics of SKH 57 high-speed steel were investigated. A well-designed experimental scheme was used to reduce the total number of experiments. Parts of the experiment were conducted with the L18 orthogonal array based on the Taguchi method. Moreover, the signal-to-noise ratios associated with the observed values in the experiments were determined by ANOVA and F-test. The significant parameters that critically influenced the machining characteristics were examined, and the optimal combination levels of machining parameters for material removal rate, electrode wear rate, and surface roughness were determined.