Machined Surface Finish Research Articles

Accurate synthesis of sensor-to-machined-surface image generation in carbon fiber-reinforced plastic drilling

Delamination is a prevalent issue in carbon fiber-reinforced plastic (CFRP) drilling, significantly compromising the mechanical properties of the material. Considering that delamination can impact the long-term durability of the final products, it is essential for operators to promptly identify it. This paper proposes a machined surface image generation model, called Sensor2Image, that employs time-series force sensor data as input and generates drilled-hole surface images as output. Sensor2Image first encodes the force sensor data into images using the Gramian angular field (GAF) method. Subsequently, it applies an image-to-image translation technique to generate the final machined surface images. The proposed model was trained and evaluated using experimental data gathered from drilling CFRP specimens under an industrial robot machining system. The results demonstrated the versatility of the proposed model for practical applications, regardless of the delamination factor. The proposed method offers significant advantages over existing methods through its intuitive visual representation approach. It facilitates the visual inspection of delamination while enabling surface quality analysis of the drilled hole and identification of defects or irregularities that may impact the mechanical properties of the material. The proposed approach can enhance the efficiency and reliability of industrial processes, particularly those involving complex delamination factors. It is a valuable tool for optimizing the CFRP drilling process and enhancing drilled-hole quality in a user-friendly manner.

Effect of metallic substrate and rubber elastic materials over passive constrained layer damping on tool vibration during boring process

Tool vibration is a key factor that affects surface finish, generates noise, and reduces the tool life during conventional boring because of the excessive overhanging length of the tool holder. The interaction between the dynamics of the machine tool and the boring process led to progressive vibration. The creation of appropriate mechanisms in reducing tool vibration will help manufacturing industries to become more productive. In this research, in order to control vibration in the overhanging boring bar, a passive vibration control method was employed. Constrained layer dampers consist of boring bar, substrate, and elastic materials and it is used to minimize tool vibration produced during boring operation. The investigation utilized computational analysis through the ANSYS Workbench platform, employing key parameters such as the overhanging length of the tool holder (100, 150, and 200 mm), substrate material (aluminum, brass, and copper), and elastic material (Nitrile rubber, Natural rubber, and polyurethane). A comprehensive series of 27-run boring experiments were conducted to assess the impact of the constrained layer damper on tool vibration and cutting properties. The results of the study revealed remarkable improvements in various performance metrics. The constrained layer damper demonstrated an impressive 98% reduction in tool vibration, signifying its efficacy in dampening vibrational forces during the boring operation. Furthermore, a substantial 83% decrease in surface roughness was observed, indicating enhanced machining precision and surface finish. The constrained layer damper also exhibited a noteworthy 97.5% reduction in tool wear, highlighting its ability to significantly prolong tool life under challenging machining conditions.

Comprehensive stratified K-fold machine learning for surface roughness prediction with 3D printed electrodes: Analyzing dielectric variability and heat treatment effects

Electrical discharge machining (EDM) is popular for its accuracy in cutting difficult materials. Material removal rate (MRR), electrode wear ratio (EWR) and surface roughness (SR) are deemed as the success indicators in EDM. The positive attributes of sustainable manufacturing make it a suitable choice for diverse applications. EDM electrodes used in this work are prepared by 3D printing and further subjected to deep cryogenic treatment (DCT) to investigate the influence of heat treatment on EDM performance. In the second instance, the experiments are conducted with different dielectric fluids viz. conventional dielectric (CD) and lemon peel biodiesel dielectric (LPD) to analyze the impact of dielectric change. When the dielectric is changed to lemon peel biodiesel, the roughness of the electro-discharged machined surface is reduced to a maximum of about 33%. A further improvement of about 11% is possible in the surface finish of machined surfaces when the EDM electrodes are subjected to DCT under an identical operating condition. LPD as dielectric also helps in attaining the primary objective of green manufacturing by reducing specific evaporative emissions. During the EDM process, LPD adoption causes a reduction of 96% in nitrogen oxide (NO) emissions and 86% in hydrocarbon (HC) emissions. A modified adaptive neuro fuzzy inference system (ANFIS) with a stratified k-fold machine learning approach with a prediction accuracy of about 95% is also developed in this work to envisage the surface roughness of electro-discharge machined surfaces.

Development of Electrochemical Microtextured Cell for Fabrication of Complex Micropattern

Introduction: This paper highlights the representative patents related to the application of maskless electrochemical micromachining (EMM) using microtextured tools and developed cells under electrolysis conditions for the generation of high-quality complex patterns, i.e., cascade micropattern on stainless steel. background: Electrochemical Microtextured Cell Method: To acquire high accuracy level, the workpiece and tools are fixtured properly in the developed microtextured cell, and a developed vertical cross-flow system is utilized for the generation of a precise cascade micropattern. An electrochemical microtextured cell is designed and developed inexpensively for the fabrication of high-quality complex micropatterns. The eco-friendly combined electrolyte of NaNO3 and NaCl is employed for precise micro texturing. Result: The consequence of predominant input factors, i.e., IEG, voltage, and flow rate, are explored on machining rate, precision, depth, and surface finish during complex micro-texturing using developed microtextured cells. The complex microtextured tool is fixtured in tool holding device in a developed microtextured cell and fabricates nineteen precise complex micropatterns. Conclusion: An effort has been made to find suitable input factors for the generation of precise complex micropatterns.

Investigations on the relationship between surface roughness and process variables of die sinking electro-discharge machining

Achieving a high-quality surface finish in electro-discharge machining (EDM) poses challenges compared to other machining methods. It necessitates separate finishing operations following one or more roughing stages. The precise connection between surface roughness and the influencing factors remains unclear. Existing literature tends to prioritize material removal rates and relative electrode wear over surface roughness. Additionally, previous investigations into evaluating surface roughness performance in die sinking EDM have typically examined only a limited number of variables at a time, despite the involvement of multiple parameters in the process. In the present work, a deeper understanding of how process variables impact surface finish quality were studied. Experiments were conducted on die steel workpieces, varying seven key parameters: pulse current, pulse width, gap voltage, dielectric flow rate, tool material, duty cycle, and servo feed, with the goal of achieving a superior surface finish. To assess the significance of these controlling variables and their interactions, the experimental results were analyzed using ANOVA (Analysis of Variance). Subsequently, a generalized equation is developed that elucidates the relationship between surface roughness and process variables. Furthermore, confirmatory tests were conducted to validate our chosen methodology.

Efficient cutting path planning for a non-spherical tool based on an iso-scallop height distance field

Iso-scallop height machining means, when machining a freeform surface, the scallop height between any two neighboring tool paths on the surface will be a constant (i.e., the given threshold), which is preferable among various freeform surface machining strategies due to its high machining efficiency as well as better machine tool’s dynamics. However, all the existing iso-scallop height path planning methods pertain to only the ball-end or flat-end types of tools. In recent years, the non-spherical cutting tool has become more and more popular, especially for five-axis machining of complex freeform surfaces, majorly owing to its non-constant curvature which can be utilized to adaptively fit the tool to the surface to both avoid the local gouging and enlarge the cutting width. However, there have been no reported works on iso-scallop height five-axis tool path generation for a non-spherical tool, and, in this paper, we present one. Specifically, we first define and construct two fields on the surface to be machined-the collision-free tool orientation field (vector) and the iso-scallop height distance field (scalar). The iso-lines of the scalar field and their associated tool orientation field vectors then naturally serve as potential iso-scallop height five-axis tool paths, and we present a propagation-based algorithm to construct the desired tool path from the iso-lines. The computer simulation and physical cutting experiments confirm that everywhere on the surface, except maybe near the saddle curves of the scalar filed, the scallop height is exactly the given threshold. By adding the saddle curves as extra tool paths, the final machined surface then is assured of the required scallop height requirement.

Improving the machined surface in electrochemical mill-grinding by particle tracking fluid simulation and experimental research

The hybrid machining method called electrochemical mill-grinding is an advanced machining technology, which can achieve high-quality processing of various difficult-to-cut materials. However, achieving rapid transportation and removal of processed products within a small machining gap is a key challenge, which directly affects the final machined surface quality. In this paper, the product transport under different flushing modes was studied through numerical simulation of the flow field. By using the particle tracking method, the time required for the removal of machining products from the machining gap was dynamically simulated. The analysis results indicated that the removal speed of machining products could be significantly improved when the flushing pressure was 0.8 MPa and the electrolyte jet angle was 30°. In addition, machining experiments were conducted. The machining experiment results showed that the machined surface had a metallic luster with clear edge contours. The grinding marks on the machined surface indicated the grinding effect. The continuous machining of complex patterns demonstrated the reliability of this hybrid machining process.

Surface morphology improvement and residual stress distribution of SiCp/Al composites using high-power fiber laser-CNC milling cooperative machining strategy

This work proposes a novel high-power fiber laser-CNC milling cooperative strategy for cutting SiCp/Al composites, which aims to machine MMCs with high efficiency and limited damage, and achieve compressive residual stress distribution within machined surface layer in order to subsequently improve service performance of composite components. Experimental results shows that the cooperative machining strategy has a sufficient improvement in machining efficiency with limited surface defects compared to conventional methods. Completely removal of laser cutting induced surface defects, including striations, combustion and cataphracted dross, was achieved under high speed milling with small cutting depth down to 0.2 mm. Additionally, it was found that the roughness of final machined surface was impacted by the parameters of both laser cutting and milling process. The surface roughness decreased by 35 % with the laser power increased from 4.0 kW to 4.5 kW, while decreased by 60 % when milling speed decreased from 180 m/min to 90 m/min. Compressive residual stress was prevalent within the surface layer during fiber laser-CNC milling cooperative machining process. The experimental findings in this work verified the feasibility and advantages of the cooperative machining strategy for processing difficult-to-cut metal matrix composites.

Compensating varying size effect in diamond cutting of SiCp/Al by ultrasonic elliptical vibration

The heterogeneous mechanical properties of individual phases in SiCp/Al result in significant varying size effect (SE) existed in its deformation process. And modulating the varying SE is crucial for improving the machined surface finish of SiCp/Al in mechanical machining. In this study, we elucidate the mechanisms governing the varying SE in conventional cutting and ultrasonic elliptical vibration-assisted cutting (UEVC) of SiCp/Al using diamond tools by theoretical analysis, numerical simulations and experiments. Specifically, the impact of cutting tool-workpiece contact states in UEVC on the fundamental cutting behavior of SiCp/Al, in terms of microscopic deformation modes and their correlations with machining force variation, machined surface morphology and chip profile, is evaluated. Subsequently, ultrasonic elliptical vibration-assisted diamond turning of SiCp/Al is performed to achieve a surface roughness of 20 nm accompanied with significantly suppressed tool wear. Finally, the compensation effect on the varying SE in SiCp/Al cutting by ultrasonic elliptical vibration of cutting tool is discovered, which leads to decreased brittle fracture and improved surface integrity. The research findings provide a theoretical support for understanding the machining mechanisms of UEVC of SiCp/Al, as well as proposing new perspectives for improving the machinability of SiCp/Al composite accompanied by suppressed varying SE.

Vibration modelling analysis of defective parallel robots as machine tools for aerospace parts machining

The strict machining accuracy and surface finish requirements of manufactured products for aerospace parts make it particularly crucial to analyse the vibration performance of parallel robots as machining tools, which directly affects both of these factors. In this paper, a vibration modelling analysis for parallel robots with fewer-DOFs called defective parallel robots is presented, and the effects of four vibration models are also studied. The traditional spring-damping or elastic vibration models of two systems are presented, and the corresponding uncertain vibration systems are developed by considering the effects of gravity and the uncertain joint clearances. Taking a drilling defective parallel robot as an application example, four vibration models are derived, and the differences in natural frequency and vibration response are explored in numerical and experiment comparisons. The results shows that an uncertain system with six DOFs is closer to the experimental result (approximately 75.49%) than an elastic system (approximately 62.39%), which means that the accuracy has increased by 13.1%. The results of this paper reveal some of the reasons for the performance errors of the different vibration models for defective parallel robots, and the findings of this paper can provide a reference for the simplification and optimization of theoretical vibration models that ignore secondary factors.

Effect of Refresh Time on XeF2 Gas-assisted FIB Milling of GaAs

Focused ion beam (FIB) machining can be used to fabricate gallium arsenide-based devices, which have a surface finish of several nanometers, and the FIB machining speed and surface finish can be greatly improved using xenon difluoride (XeF2) gas-assisted etching. Although the refresh time is one of the most important parameters in the gas-assisted etching process, its effect on the machining quality of the surface finish has rarely been studied. Therefore, in this work, we investigated the effect of the refresh time on the etching process, including the dissociation process of XeF2, the refresh time dependency of the sputter in yield under different incident angles, and the surface finish under different refresh times. The results revealed that a selective etching mechanism occurred at different refresh times. At an incidence angle of 0°, the sputtering yield increased with the refresh time and reached its maximum value at 500 ms; at an incidence angle of 30°, the sputtering yield reached its minimum value at a refresh time of 500 ms. For surface roughness, the incident angle played a more important role than the refresh time. The surface finish was slightly better at an incidence angle of 30° than at 0°. In addition, both F and Xe elements were detected in the processed area: Xe elements were evenly distributed throughout the processing area, while F elements tended to accumulate in the whole processing area. The results suggest that the optimum surface can be obtained when a larger refresh time is employed.

High-frequency ultrasonic vibration-assisted sculpturing with a smoothed tool path for optical 3D micro-structured surfaces with sharp edges

The fabrication of complex 3D micro-structured surfaces on difficult-to-machine materials such as steel and tungsten carbide is the premise for mass production of glass components with functional surfaces by the glass moulding process. Ultrasonic vibration-assisted cutting (UVAC) is an effective method to machine 3D micro-structured surfaces on these difficult-to-machine materials. However, it is challenging and difficult for UVAC to machine microlens arrays with sharp edges, at which sudden acceleration of the z-axis slide is required to make the cutting tool follow the tool path. This could induce tool vibration and cause relative tool-work displacement, resulting in poor machining accuracy and surface finish of the machined 3D microstructure. In this paper, high-frequency ultrasonic vibration-assisted sculpturing (HFUVAS) with a smoothed tool trajectory is used to machine microlens array on steel mould for fine machining accuracy and surface quality. A comparison is made between the cutting performance of the circular microlens arrays machined by diamond turning and diamond sculpturing. The results found that relative tool-work displacement arising at sharp edge in diamond turning could be eliminated in HFUVAS with a smoothed tool path, demonstrating the effectiveness of a smoothed tool path in reducing relative tool-workpiece displacement in the fabrication of 3D micro-structured surfaces. Furthermore, a quadrilateral microlens array and hexagonal microlens array are also fabricated in order to extend the applications of HFUVAS, with a form error within 1 μm and surface roughness with an arithmetical mean height Sa of below 10 nm achieved.

Time Parameter Mapping and Contour Error Precompensation for Multiaxis Input Shaping

When the trajectory with high speed and high acceleration contains frequency contents matching with the structure mode, the inertial vibration of the structure is easily excited, reducing machining accuracy and surface finish. Input shaping can avoid vibration, but it introduces time-delay that causes multiaxis trajectory distortion and affects the accuracy of contour error estimation. This article presents time parameter mapping and contour error precompensation for multiaxis input shaping to suppress vibration. The mapping of time parameter domain of trajectories is established by deducing the relation between the local curvature extremums of the trajectories before and after shaping, which provides reference points for contour error estimation. The actual trajectory is predicted by the closed-loop servo dynamics model and reference trajectory, and then the Newton iterative algorithm based on time parameter mapping is used to seek the contour error point. Finally, the calculated contour error is low-pass filtered and projected to each axis, and then the shaped trajectory is precompensated to simultaneously reduce the contour error and avoid structural vibration. Comparative experiments are conducted to validate the effectiveness of the proposed method. Experimental results illustrate that the proposed method not only suppresses structural vibration, but also significantly improves the estimation accuracy and contouring performance by time parameter mapping.

Investigation on microstructure characteristics of tool wear and machined surface mechanisms while milling: kenaf vs glass fiber-reinforced composites

In composites' secondary/machining process, there is still a requirement for a comparative assessment of microstructure features of tool wear and machined surface mechanisms while machining natural fiber against glass fiber-based composites. This experimental study uniquely investigates the dry-end milling of two polypropylene (PP)-based composites made of 30 wt.% discontinuous reinforcements - kenaf and glass fibers (GF). Surprisingly, though, GF are much harder (GF:5.84 GPa > kenaf:0.15 GPa) and abrasive (silicon content, GF:24.16% > kenaf:0.57%) than kenaf inclusions, cutting GF/PP resulted in relatively lower tool wear (≈0.08 mm) but contrarily showed adverse machined surface finishes (>8 μm) depicting tearing-dragging mechanisms with fuzzy textures. This cautions on the appropriate consideration for the tool's life-determining criterion – i.e., whether it should be based on the tool wear or surface finish. While machining GF/PP material, the tool wear growth on the cutting edges was significantly restricted by the formations of continuous-robust microstructural transfer protective film (TPF) characterized by strong Si + O, Al + O, and Fe + O tribo-chemical reactions through the interesting wear mechanisms associated with tribological phenomena. However, thin-patch type microstructural TPFs consisting of weak Si + C bonds occurred on tool edge regions while machining kenaf/PP. Better mechanical properties and fiber-matrix adhesion of GF/PP influenced by fiber dimensions and their higher aspect ratios (GF:27.60 > kenaf:7.20) decisively seem to have a dominant effect on limiting the tool wear. Chip micrographs clarified the cutting of GF/PP and kenaf/PP occurred by predominant melt-extrusion and shearing respectively.

Investigation on Surface Integrity in Hard Turning of AISI 4140 Steel with SPPP-AlTiSiN Coated Carbide Insert under Nano-MQL

The machined surface integrity in the turning of hardened steels is adversely influenced by heat generation and friction which requires pacification of the temperature by the effective cooling-lubrication approach and cutting tool performance. The present research analyzes the surface integrity of hardened AISI 4140 steel during turning with recently developed scalable pulsed power plasma SPPP-AlTiSiN coated carbide tool under nanofluid-assisted minimum quantity lubrication (MQL). Zinc oxide nanoparticles and environmentally friendly radiator coolant are mixed to prepare the nano cutting fluid. This analysis addresses the various aspects of surface integrity concerning surface morphology, machined surface hardness, residual stress and white layer development, and machined surface finish under varying cutting parameters (depth of cut, speed, feed, nose radius). Response surface methodology (RSM) is suggested to predict and to optimize the surface roughness in hard turning. Thereafter, the predictive modelling and optimization results are implemented for economic analysis. According to the findings of the experiments, with a contribution of 58.18%, the feed rate possesses a high impact on the surface finish, followed by the nose radius (12.32%) and speed (0.85%). Consequently, the machined surface quality improved with the increase of the nose radius because of the minimum tool wear and due to the increase of the effective length of the cutting edge. At optimum cutting conditions, the tool life of SPPP-AlTiSiN coated carbide insert is noted as 46 minutes under nanofluid-MQL and consequently, it estimated the overall machining cost per component as Rs.23.12 in Indian currency.

Investigation on the Performance of Coated Carbide Tool during Dry Turning of AISI 4340 Alloy Steel.

The machinability of materials is highly affected by their hardness, and it affects power consumption, cutting tool life as well as surface quality while machining the component. This work deals with machining of annealed AISI 4340 alloy steel using a coated carbide tool under a dry environment. The microhardness of annealed and non-annealed workpieces was compared and a significant reduction was found in the microhardness of annealed samples. Microstructure examination of the annealed sample revealed the formation of coarse pearlite which indicated a reduction of hardness and improved ductility. A commercially CVD multilayer (TiN/TiCN/Al2O3/ZrCN) coated cemented carbide cutting tool was employed for turning quenched and tempered structural AISI 4340 alloy steel by varying machining speed, rate of feed, and depth of cut to evaluate the surface quality, machining forces, flank wear, and chip morphology. According to the findings of experiments, the feed rate possesses a high impact on surface finish, followed by cutting speed. The prominent shape of the serrated saw tooth chip was noticed at a higher cutting speed. Machined surface finish and cutting forces during turning is a function of the wear profile of the coated carbide insert. This study proves that annealing is a low-cost and economical process to enhance the machinability of alloy steel.

Experimental Analysis of (triaxial /3D) Machining Cutting Forces and Surface Roughness in Turning Operation OF EN8 Steel

Abstract: The measurement of all machining forces and surface finish during the turning process. All types of machining process the cutting tool, workpiece of surfaces roughness, tool wear, quality, and accuracy of the part of machining the present study.to investigate the effect of machining input parameters (spindle speed, feed rate, depth of cut) on measuring the forces after machining (cutting force, feed force, thrust force) and surface roughness for turning operation. Using of workpieces is EN8 steel and a cutting tool is a carbide tool. experiment stabilized on the lathe machine. The force is measured by a triaxial piezoelectric sensors base dynamometer and data is transmitted by a data aquation system. this is controlled by LAB-VIEW software and stores the forces in the computer. there are 27 experiments, and one parameter is changed and two parameters are constant at an experiment. measured the forces and (Ra) is analyzed is by minitab18 software design a regression equation and (ANOVA). The minimum force and (Ra) the experimental (force &surface roughness is nearest to the predicted value

Material removal and surface damage in high-speed grinding of enamel

Although high-speed grinding of the enamel surface is often required in restorative dentistry, the knowledge of grinding mechanics, material removal, and fracture damage mechanism related to this process is still relatively limited; therefore, it is important to perform relevant scientific and theoretical research. As per the occlusal surface and the buccal/lingual surface of the teeth, the experimental scheme of high-speed grinding of the enamel surface using a diamond grinding bur was designed, and the grinding force, force ratio, grinding temperature, chips, surface morphology, surface damage, and other important characteristics were tested and analyzed. Furthermore, the grinding geometry model, grinding mechanics, material fracture, and removal mechanism associated with the high-speed grinding of an enamel surface were considered. The results show that the grinding force, friction coefficient, grinding temperature, and surface damage achieved through buccal/lingual surface grinding are considerably greater, and the grinding quality is worse than that obtained via occlusal surface grinding under the same grinding conditions. With the increase in the feed rate, grinding force, friction coefficient, grinding temperature, and surface damage obviously increase, and the surface quality decreases. The embrittlement effect and the ironing mechanism are present during the process of high-speed grinding of enamel. Regardless of the feed rate, the three types of material fracture modes of the buccal/lingual surface are more serious than those of the occlusal surface (making it more likely to produce unstable large chips or tearing chips); moreover, the brittle fracture and damage of the final machined surface are more obvious. The cutting mechanics and cutting mechanism identified in this study will provide scientific guidance for dental grinding operations.

Turning of hardened AISI H13 steel with recently developed S3P-AlTiSiN coated carbide tool using MWCNT mixed nanofluid under minimum quantity lubrication

This article aims to analyze the tool vibration, surface roughness, and chip morphology in hard turning of hot work AISI H13 steel under multi-walled carbon nanotubes mixed nanofluid with minimum quantity lubrication. Recently developed new-generation nanocomposite AlTiSiN coating deposited on carbide insert via scalable pulsed power plasma (S3P) strategy is used as cutting tool material. The experiments associated with 30 number of trials are performed by considering various machining parameters that includes cutting speed, nose radius, depth of cut, and feed. In perspective of predictive modeling and multi-response optimization, response surface methodology has been engaged as a means to minimize the tool vibration and surface roughness. At last, with the measured tool life and based on the Gilbert’s machining economic model, a distinctive cost analysis has been implemented to demonstrate the cost-effectiveness of coated carbide tool in hard turning. Statistical analysis confirms that nose radius with 36.65% has the highest contribution for surface roughness and cutting speed with 53.88% has the highest contribution for tool vibration. Increased flank wear and tool vibration are responsible for degradation of machined surface finish. Machining under nanofluid-MQL, chip morphology revealed the production of segmented type serrated saw-toothed chips. At higher cutting speed resulted: (a) obvious shape of saw tooth chip, (b) increase of distance among saw tooth, (c) reduction in chip segmentation frequency, (d) decrease of chip thickness. At optimum combination of process variables ( v = 55 m/min, d = 0.2 mm, r = 1.2 mm, f = 0.07 mm/rev), the life of AlTiSiN coated carbide tool is found to be 42 min under nanofluid-MQL and estimated the total machining cost expenditure per finished part of Rs. 153.52. New-generation AlTiSiN coated carbide tools can be competently and productively utilized for machining of hot work tool steel under ecologically cognizant minimum quantity cooling-lubrication, is the most accepted in industrial applications.

Experimental Investigation of Powder-mixed Dielectrics for Electrical Discharge Machining

The addition of various micro/nanopowders in the EDM dielectric results in superior machining performance over the conventional pure liquid dielectrics. While most of the experimental studies on powder-mixed dielectrics in EDM have used conductive or semi-conductive powders, a few have shown merit in using non-conductive powders as well. However, unlike conductive powders, the specific mechanisms through which the non-conductive powders and their concentration affect the EDM process is poorly understood. The research presented in this paper investigates the effect of non-conductive powders and their concentration on the machining performance of powder-mixed dielectric-based EDM (PMEDM) in terms of material removal rate, tool wear, and surface roughness. Experiments are conducted with Alumina and SiC powder added to DI water at three different concentrations. It is observed that the material removal rate (MRR) and tool wear rate (TWR) of PMEDM is higher than conventional EDM with pure dielectric, while the electrode wear ratio is lower. The machined surface finish is smoother in PMEDM than conventional EDM. In Alumina-based PMEDM, an increase in the powder concentration leads to inter-electrode gap enlargement due to increased electrical conductivity, and leads to higher pulse frequency, stable machining conditions and improved MRR. In addition, dispersion of discharge energy due to the powder results in a better surface finish. The conductivity of SiC-mixed dielectric remains unaffected with changes in powder concentration, leading to no significant improvements in MRR. However, the energy dispersion mechanism leads to a smoother surface as the powder concentration increases.