Modeling and Analysis of Micro-hole in Die-sinking EDM Process through Response Surface Method based on the Central Composite Design

A novel aluminium metal matrix composite reinforced with SiC particles were prepared by liquid metallurgy route. Recent developments in composites are not only focused on the improvement of mechanical properties, but also on machinability for difficult-to-machine shapes. Electrical discharge machining (EDM) was employed to machine MMC with copper electrode. using EDM. Experiments were conducted using pulse current, gap voltage, pulse on time and pulse off time as typical process parameters. The experiment plan adopts face centered central composite design of response surface methodology. Analysis of variance was applied to investigate the influence of process parameters and their interactions viz., pulse current, gap voltage, pulse on time and pulse off time on material removal rate (MRR), electrode wear ratio (EWR) and surface roughness (SR). The objective was to identify the significant process parameters that affect the output characteristics. Further a mathematical model has been formulated by applying response surface method in order to estimate the machining characteristics such as MRR, EWR and SR.

The wire electrical discharge machining (WEDM) allowed success in the manufacture of the hard, fragile, and materials difficult to cut, especially for electroconductive ceramic materials. In this study, the mathematical models of material removal rate (MRR) and surface roughness (SR) used for the machinability evaluation in the WEDM process of aluminum oxide-based ceramic material (Al2O3 + TiC) have been carried out. The experimental plan adopts the face centered central composite design (CCD). The mathematical models using the response surface methodology (RSM) are developed so as to investigate the influences of four machining parameters, including the peak current, pulse on time, duty factor, and wire speed, on the performance characteristics of MRR and SR. It has been proved that the proposed mathematical models in this study would fit and predict values of the performance characteristics, which would be close to the readings recorded in experiment with a 95% confidence level. The significant parameters that critically affect the performance characteristics are examined.

Corrosion resistant high entropy conventional alloy (HECA) with superior work hardenability

The present work is aimed at optimizing the cutting rate (CR), surface roughness (Ra) and dimensional deviation (DD) in wire electrical discharge machining (WEDM) of EN-31 steel considering various input parameters such as pulse-on-time, pulse-off-time, wire tension, spark gap set voltage and servo feed. A face centered central composite design of response surface methodology (RSM) has been adopted to develop the empirical model for the responses. It is often desired to obtain a single parameter setting that can decrease Ra and DD and increase CR simultaneously. Since the responses are conflicting in nature, it is difficult to obtain a single combination of cutting parameters satisfying all the objectives in any one solution. The optimum search of the machining parameter values for maximization of CR and minimization of Ra and DD are formulated as a multi-objective, multi-variable, nonlinear optimization problem using genetic algorithm weighted sum method to evaluate the performance.

Titanium alloys find wide applications in aerospace, defence, and surgical industries due to their unique high strength- to- weight ratio which is maintained even at high temperatures and also their exceptional corrosion resistance. The machining of these materials is a thermally dominant process. At high temperature, they become chemically active and tend to react with tool materials. In the present study an attempt has been made to investigate the effect of cutting parameters (cutting speed, feed rate and depth of cut) on surface roughness in turning a Ti6Al4V Titanium alloy with a medium temperature chemical vapor deposition tool insert. Experiments have been conducted using Taguchi’s experimental design technique. Optimum cutting parameters for minimizing surface roughness have been determined by using the desirability function based approach. A second order model has been established between the cutting parameters and the surface roughness, using the response surface methodology. Predicted values and measured values fairly tally and it indicates that the developed model can be effectively used to predict the surface roughness in the machining of Ti6Al4V Titanium alloy. Experimental results reveal that among the cutting parameters, the feed rate is the most significant machining parameter for surface roughness, followed by depth of cut and cutting speed.

9Cr18MoV stainless steel is widely employed in cutting-tool applications owing to its exceptional hardness and corrosion resistance. In this study, we systematically optimized the wire electrical discharge machining (WEDM) process parameters for 9Cr18MoV stainless steel through an L16 (44) orthogonal experimental design. The key parameters investigated include pulse width (Ton), pulse interval (Toff), peak current (IP), and wire feed speed (WS), with cutting efficiency (CE) and surface roughness (Ra) serving as the primary optimization objectives. A signal-to-noise ratio (SNR) analysis was applied to assess the effects of the individual parameters and derive single-objective optimal configurations. Subsequently, grey relational analysis (GRA) integrated with analytic hierarchy process (AHP)-based weighting was employed to establish a multi-objective optimal parameter set, which was experimentally validated. The results reveal that the optimal multi-objective performance was attained at Ton = 28 μs, Toff = 3 μs, IP = 9 A, and WS = level 3. SEM characterization confirmed that this parameter combination yields a more uniform surface morphology, with diminished oxidation and molten debris deposition, thereby significantly enhancing surface integrity. The adoption of this optimized parameter set not only ensures superior machining efficiency but also results in improved surface quality.

Mathematical modeling of aerosol emission from die sinking electrical discharge machining process

Aim: The aim of the present study was to increase the solubility and dissolution of Glibenclamide. Materials and Methods: Various batches of solid dispersion of Glibenclamide using water soluble carriers such as PEG (PEG 4000 and PEG 1500), were prepared as per the design expert (8.0.5) to optimize the drug release profile using response surface methodology (Face centered central composite design). Results: DSC and FTIR were used to characterize the solid dispersions. No chemical interaction was found between Glibenclamide and polymers. F3 and F13 was found to be optimized batch according to the Face centered central composite design (FCCCD). Conclusion: Drug release was directly proportional to the concentration of polymer used for the formulation of solid dispersion. Thus, Glibenclamide with PEG 4000 and PEG 1500 had faster dissolution rate than Glibenclamide itself. Key words : Solid Dispersion, Dissolution, Physical Mixture, Polyethylene Glycol.

ABSTRACTInvestigation on the machining of Aluminium Matrix Composites (AMCs) through non-conventional approach are the current attention over the conventional machining approach of those may produces additional complexity in industrial manufacturing. The current research focused on investigating the machinability characteristics of the newly prepared compocasted AA6061/ cenosphere AMCs implementing a non-traditional material removal process via spark erosion called Electro Discharge Machining (Wire-EDM). The performance measure of the system for the different combinations of independent process variables were considered as cutting rate (CR), Kerf Width (KW) and Surface Roughness (SR). Experimental design were carried out based on Response Surface Methodology (RSM) employed face centered Central Composite Design (CCD) required for the analysis. A hybrid approach comprises of grey relation theory in conjunction with RSM Grey- Response Surface Methodology (GRSM) were executed for the prediction of optimal settings of machining condition which yield the optimum performance characteristics of the system. The model fit summary revealing an adequate fitness of the developed model to the actual system, as the R-square value was found to be 0.9607,close to unity and a larger (<4.0) adequate precision value of 20.87. Noticeable improvement were attained on cutting speed (3.234%), kerf width (2.7415%) and surface roughness (7.053%) implementing the optimal setting of machining parameters based on the proposed hybrid GRSM approach. Generous improvement was also noticed on the 3D optical Wire Electro Discharge (WED) machined surface texture demonstrating the quality of surface roughness and texture using hybrid GRSM predicted processing conditions.

Electrical Discharge Machining (EDM) consists of a non-conventional machining process, which is widely used in modern industry, and especially in machining hard-to-cut materials. By employing EDM, complex shapes and geometries can be produced, with high dimensional accuracy. Titanium alloys, due to their unique inherent properties, are extensively utilized in high end applications. Nevertheless, they suffer from poor machinability, and thus, EDM is commonly employed for their machining. The current study presents an experimental investigation regarding the process of Ti–6Al–4V ELI with high power EDM, using a graphite electrode. Control parameters were the pulse-on current (Ip) and time (Ton), while Machining performances were estimated in terms of Material Removal Rate (MRR), Tool Material Removal Rate (TMRR), and Tool Wear Ratio (TWR). The machined Surface Roughness was calculated according to the Ra and the Rt values, by following the ISO 25178-2 standards. Furthermore, the EDMed surfaces were observed under optical and SEM microscopy, while their cross sections were also studied in order the Average White Layer Thickness (AWLT) and the Heat Affected Zone (HAZ) to be measured. Finally, for the aforementioned indexes, Analysis Of Variance was performed, whilst for the MRR and TMRR, based on the Response Surface Method (RSM), semi-empirical correlations were presented. The scope of the current paper is, through a series of experiments and by employing statistical tools, to present how two main machining parameters, i.e., pulse-on current and time, affect major machining performance indexes and the surface roughness.

Titanium and its alloys are attractive materials due to their unique high strength–weight ratio that is maintained at elevated temperatures and their exceptional corrosion resistance. The major application of titanium has been in the aerospace industry. On the other hand, titanium and its alloys are notorious for their poor thermal properties and are classified as difficult-to-machine materials. The problems that arise during grinding of titanium alloys are attributed to the high specific energy and high grinding zone temperature. Significant progress has been made in dry and semidry machining recently, and minimal quantity lubrication (MQL) machining in particular has been accepted as a successful semidry application because of its environmentally friendly characteristics. A number of studies have shown that MQL machining can show satisfactory performance in practical machining operations. However, there has been few investigation of MQL grinding of special alloys like titanium alloys and the cutting fluids to be used in MQL grinding of these alloys. In this study, vegetable and synthetic esters oil are compared on the basis of the surface quality properties that would be suitable for MQL applications. The cutting performance of fluids is also evaluated using conventional wet (fluid) grinding of Ti–6Al–4V. As a result, synthetic ester oil is found to be optimal cutting fluids for MQL grinding of Ti–6Al–4V.

An environmentally friendly coating: Excellent self-cleaning, efficient antimicrobial, and durability properties

HEA-NiFeCuCoCe/NF through ultra-fast electrochemical self-reconstruction with high catalytic activity and corrosion resistance for seawater electrolysis

AA6061-T6 aluminum alloy (Al–Mg–Si alloy) has gathered widespread acceptance in the fabrication of light weight constructions necessitating high strength-to-weight ratio and good corrosion resistance. In this study, ultra-fine grained (UFG) structure (~0.65 µm) was produced in the stir zone (SZ) of AA6061-T6 alloy joints using friction stir processing (FSP) cooled by liquid nitrogen (N2). A new experimental set-up was designed and used to simultaneously quench the lower and upper surfaces of weldments during the processing. The temperature changes were monitored via attaching thermocouples (K-type) to samples. In addition, a conventional solid state welding technique, friction stir welding (FSW), was used to fabricate reference joints. Micro- and sub-structural studies were carried out to using high resolution EBSD. The corrosion properties of the cooled joints were investigated by potentiodynamic polarization and NaCl-induced atmospheric corrosion tests. The atmospheric corrosion exposures were carried out at a relative humidity (RH) of 95%, 400 ppm CO2 and at 22°C. Crystalline corrosion products formed on the surface of the samples were identified by X-ray diffraction (XRD). The rapidly cooled joints exhibited exceptional corrosion resistance in both corrosion experiments as well as better mechanical properties compared to those of the FSWed joints.

Investigation of Zn alloy coating with submicron phases on magnesium alloy by the novel hot-dip process