Workpiece Surface Research Articles

Effect of pad surface morphology on the surface shape of the lapped workpiece

Double-sided lapping is currently the mainstream manufacturing method for obtaining plane-parallel optical workpieces with high surface shape accuracy, and the fixed abrasive lapping pad is the main machining tool. However, the effect of pad surface morphology on the workpiece surface shape has rarely been studied, and its formation mechanism has not yet been revealed. In this paper, based on probabilistic statistics and contact mechanics, an analytical model that takes into account the pad surface morphology for predicting the workpiece surface shape evolution is developed. Notably, this model considers the cross-scale relationship between the formation of lapped surface shape and the scratching process of a single abrasive grain in material removal for the first time. Furthermore, the real-time dynamical contact relationship between the workpieces and the measured actual pad surface morphology is also considered. The surface shape and peak-to-valley value of the workpiece under different parameters were simulated and analyzed, and the influence mechanism of the local profile and macro shape of the lapping pad on the lapped workpiece surface shape are clarified. Moreover, the double-sided lapping trial experiments were performed to validate the theoretical model, and the experimental results demonstrated good agreement with the simulation results. The maximum error of the surface shape evolution prediction model is less than 14.6 %. This result verifies the correctness and validity of the established model. This work not only provides new ideas for controlling the workpiece surface but also forms the theoretical basis for understanding the double-sided lapping process.

Study on the dynamic influence of the distribution of cutting depth on the ground surface quality in a precision grinding process

Focusing on the excitation mechanisms of self-excited vibration and forced vibration, a time-delay differential model of the radial cutting depth of a single active abrasive grit is presented. Based on the principle of the layered superposition characteristics of each component of radial cutting depth, a full discrete simulation technology is used to analyze the dynamic mechanisms of different vibration excitations on the grinding characteristics. The reliability of the dynamic mechanisms is verified by the corresponding grinding experiments. The verification results demonstrate that static and dynamic components in the grinding dynamics, including radial cutting depth, grinding force, surface roughness and surface morphology of workpiece are greatly influenced by total material removal rate, followed by speed ratio and grinding directions. With the increase of cutting depth, the variation amplitude of grinding process influenced by forced-vibration mechanism are nearly twice larger than those influenced by self-excited vibration mechanism. When speed ratio reduces to a half, surface roughness of workpiece improves by nearly 33 %. The stability of machining process and finish surface of workpiece during up-grinding are better than those during down-grinding, where force reduction by up to 10 % and surface finish improvement by 37 %.

Atomistic study on the effect of the size of diamond abrasive particle during polishing of stainless steel

Nanofinishing or polishing helps to reduce surface roughness, which further improves both the optical and chemical properties of engineering materials. During the polishing of any engineering material, the size of abrasive particles plays a significant role in efficient polishing. In this paper, stainless steel 304 (or SS304) is selected for polishing through diamond abrasives with varying particle sizes using molecular dynamics simulations (MDS). It is found that the diamond abrasive particle initially causes elastic deformation due to the attractive force between the abrasive particle and the workpiece surface. As the size of the abrasive particle increases, plastic deformation occurs by spreading the dislocations on the surface only, which helps to annihilate the dislocations after polishing. It is revealed that the smaller abrasive particles (<3 nm) get trapped due to strong chemical bonding with the surface of the workpiece, and the abrasive particles start depositing on the workpiece instead of material removal. In this paper, it is proposed that an optimum size of abrasive particles is required for a given set of polishing parameters to achieve efficient material removal and minimum surface and subsurface defects. Thus, the present study is worthwhile for efficient polishing or nanocutting of stainless steel through monocrystalline diamond.

Identification of milling information and cutter-workpiece engagement in five-axis finishing of turbine blades based on NURBS and NC codes

Five-axis milling is frequently used for machining of turbine blades. Cutting force can cause deformation and vibration of blades, which will eventually affect the milling accuracy and surface quality. Modeling of cutter-workpiece engagement (CWE) is a key process to predict cutting force, especially for complex tool geometries and workpiece surfaces. In this paper, a method to modeling ball-end cutter CWE boundaries for blades with free-form surfaces is presented. Firstly, the NURBS theory is employed to get the surfaces before and after finishing. Secondly, milling information such as coordinate systems is extracted from NC codes. Thirdly, the CWE boundaries are extracted based on the NURBS surfaces and extracted information. The proposed model is a combination of discrete and analytical method. Finally, the performance of CWE model is examined from computational accuracy and efficiency, and is verified through milling test. The proposed method provides a visualization of complex engagement between tool and blade in five-axis milling process, and can be further used in simulation of milling force, vibration and deformation.

Influence of the metal coating on nano-cutting process of cubic silicon carbide

The effect of the metal coating on the machinability of cubic silicon carbide was investigated by molecular dynamics simulation. The effect of the metal coating on the surface of the workpiece was explained using cutting force, friction coefficient, surface morphology, stress, temperature, and tool wear. The results show that the influence of metal type on cutting force, surface morphology, and stress is insignificant for coating thickness. However, the model with Cu coating has a tool suspension key number of 400 at the maximum cutting distance. The number of tool suspension keys for the Ni-Ti coating model is around 1700, indicating that the type of coating has a significant impact on tool wear. Furthermore, the results also show that in the three metals of Cu, Ni and Ni -Ti, Cu coating has the greatest impact on improving cutting performance. Among them, the average cutting force of 1.5 nm Cu coating is about 33.3% lower than that of without coating, and the tool wear is about 26.7% lower. These results demonstrate the effects of the metal coating on the workpiece surface from a theoretical point of view.

Multi objective optimization of process parameters in hard turning of AISI 52100 steel with surface irregularities using GRA-PCA

Dry hard-turning is a cost-effective, efficient manufacturing method for AISI 52100 hardened bearing steel. Surface Defect Machining (SDM) is a novel approach to address surface roughness, deteriorations, residual stresses, and metallurgical changes on machined steel. SDM involves exposing workpieces to surface irregularities, reducing cutting resistance, and enhancing surface integrity and finish. In the present work, surface irregularities are formed on the surface of the workpiece in the form of indentations. Using the response surface method’s central composite design (CCD), 32 experimental runs were conducted to determine the optimal process parameters by varying the cutting and tool geometry parameters while AISI52100 steel hard turning (HT). Due to its complexity, multi-objective optimization is more challenging to study. The present work aims to evaluate the effects of input parameters on maching force, surface roughness, and workpiece surface temperature. Further, machining parameters optimization is performed employing the Grey relational analysis integrated with principal component analysis (GRA-PCA). Analysis of variance (ANOVA) was used to examine the impact of cutting and tool geometry parameters on grey relational grade (GRG). ANOVA revealed that feed has the highest influence on GRG, followed by depth of cut, nose radius, cutting speed, and negative rake angle. Cutting speed of 800 rpm, feed rate of 0.04 mm/rev, depth of cut of 0.5 mm, nose radius of 1 mm, and negative rake angle of 15° are the optimum combination of process parameters.

A new algorithm for chatter quantification and milling instability classification based on surface analysis

The unstable statuses in machining, such as chatter and severe forced vibration, limit manufacturing productivity and quality. Although there have been plentiful studies on the on-line sensing signals and off-line surface images to identify these statuses qualitatively, the quantification of chatter severity, which is of great significance on machining stability, has been rarely reported. Workpiece surface morphology is the direct result and thus the objective criteria of unstable machining. This paper proposes a new algorithm to quantify the chatter status based on the milled surface image analysis of end-milling. Besides, the proposed method can also identify the stable, forced vibration, and chatter statuses. Specifically, this proposed algorithm extracts two indexes, called Index_Dmean and Index_Emean, via processing the milled surface image. The definitions and calculations of these two indexes are given in Section 2. Index_Dmean is used to differentiate stable and unstable surfaces and quantify the severity of chatter status, and Index_Emean can distinguish between forced vibration and chatter surfaces. Experimental results demonstrate the availability of the proposed algorithm on the chatter quantification and milling instability classification performance. In addition, an applicable on-line vision system with satisfying performance based on the algorithm is developed.

Influence of impact-centrifugal hardener on microhardness of workpiece surface made of aluminium alloys

This article develops a tool for impact-centrifugal processing and establishes processing modes that increase the microhardness of the surface. An experimental study was carried out, where the tightening force, the number of working strokes, the rotation frequency of the hardener and the motion were proposed as technological parameters of impact-centrifugal processing. The experiments were carried out using flat machine-cut samples based on aluminium alloy D16T. A prototype of the rotary hardener with the standard fastening was designed and manufactured. During the experiment, it was revealed that, for the variation in average microhardness, the contribution of the rotation frequency is higher than that of the longitudinal motion. A significant influence of the tension on the surface microhardness is noted: following processing with a rotary hardener, it increases. It is shown that, to a greater extent, this increase depends on the technological tightening force and to a lesser extent on the rotation speed of the tool; it is recommended to increase these parameters. It was found that a 2-fold increase in tightening force resulted in an increase in microhardness by 70 HV 0.1, while increasing the tool rotation speed by 200 rpm led to an increase in microhardness by 42 HV 0.1. However, technological parameters must be selected taking into account the operability of the hardener. It was shown that the longitudinal motion has little influence on the increase in microhardness. The prototype of the designed tool can be used for processing at milling, boring, and grinding machines with computerised numerical control through a standardised fastening unit. This ensures sufficient technological flexibility and allows it to be used for reinforcing flat surfaces and fillet radii. The forecasted increase in the surface microhardness of the D16T sample using a rotary hardener amounts to 38.5% of the initial value in the experimental area with satisfactory productivity.

Correcting distortions of thin-walled machined parts by machine hammer peening

Thin-walled aerostructural components frequently get distorted after the machining process. Reworking to correct distortions or eventually rejecting parts significantly increases the cost. This paper proposes a new approach to correct distortions in thin-walled components by strategically applying hammer peening on target surfaces of a machined component. Aluminium alloy 7475-T7351 was chosen for this research. The study was divided in two stages. First, the residual stresses (RS) induced by four different pneumatic hammer peening conditions (modifying the stepover distance and initial offset) were characterised in a test coupon, and one of the conditions was selected for the next stage. In the second stage, a FEM model was used to predict distortions caused by machining in a representative workpiece. Then, the RS induced by hammer peening were included in an FEM model to define two hammer peening strategies (varying the coverage area) to analyse the capability to reduce distortions. Two workpieces were machined and then treated with the simulated hammer peening strategies for experimental validation. Results in the test coupon showed that pneumatic hammer peening can generate high compressive RS (-50 to −350 MPa) up to 800 μm depth, with their magnitude increasing with a reduced stepover distance. Application of hammer peening over 4 % of the surface of the representative workpiece reduced the machining-induced distortions by 37 %, and a coverage area of 100 % led to and overcorrection by a factor of five. This confirms that hammer peening can be strategically applied (in target areas and changing the percentage of coverage) to correct low or severe distortions.

Multi-channel electrical discharge machining of titanium alloy Ti-6Al-4V with semiconductor electrodes

Titanium alloys are extensively used in aerospace and medical engineering owing to their exceptional mechanical properties and biocompatibility. For a long time, the low thermal conductivity of titanium alloys has made them difficult to machine with conventional approaches. Electrical discharge machining (EDM) is a nonconventional method for machining difficult-to-cut materials. However, it is not possible to achieve high-quality surface finish while simultaneously maintain high machining efficiency. This paper introduced a new EDM approach to obtain high surface quality in machining titanium alloy Ti-6Al-4V with discrete semiconductor electrodes by utilising a new multi-channel discharge principle to disperse the discharge energy. To explore the dissimilarities in discharge characteristics between semiconductor electrodes and traditional copper electrodes, continuous discharge waveforms of both electrodes were compared. Through modelling the discharge equivalent circuit and analysing workpiece surface using scanning electron microscopy (SEM), it was discovered that, due to the unique electrical properties of the semiconductor, it is possible for semiconductor electrodes to form multiple discharge channels. The outcomes reveal that the utilization of semiconductor electrodes can disperse discharge energy and enhance surface quality without sacrificing material removal rate compared to the use of conventional copper electrodes.

An Experimental Investigation of the Effects of Dressing and Grinding Parameters on Sustainable Grinding of Inconel 738 Used for Automated Manufacturing

The significant effect of the dressing process on the surface of the grinding wheel (GW) and the need to provide an optimal dressing condition are the requirements of reduction machining time and energy consumption in the sustainable grinding process. In this study, for the first time, the results of changes in the parameters of the dressing process and changes in the topography of the grinding surface on the surface roughness of the Inconel 738 have been presented using single-edge and four-edge diamond dressers. The use of minimum quantity lubrication (MQL) and wet condition are other variables in this study to reduce the consumption of cutting fluid and prevent its destructive effects on the environment. The results indicate that the MQL technique increases the grinding performance of Inconel 738 by reducing ground workpiece surface roughness and decreasing the coolant–lubricant consumption comparing to the conventional wet grinding process. Additionally, it has been found from the experimental results that applying a single-edge dresser generates finer topography on the grinding wheel and, consequently, has a better surface finish in the grinding process compared to the multipoint diamond dressing tool with the same dressing and grinding parameters. In other words, increasing the dressing feed rate during dressing of the grinding wheel using a multipoint dresser makes a finer wheel surface topography and as a result decreases the surface roughness of the ground workpiece compared to a single-edge dresser. With multipoint diamond tools, the grinding performance during the life of the dressing tool also tends to remain more consistent, which is a definite advantage in automated production. Therefore, application of a multipoint dresser leads to a reduction in dressing time and increased production capability.

Wear and residual stress in high-feed milling of AISI H13 tool steel

Abstract With the new manufacturing technologies, it has been possible to machine hard metals efficiently. During high-speed machining (HSM) of high-strength steel, the poor surface integrity of the workpiece affects the performance of the process. Surface roughness, microstructure, microhardness and residual stress are key performance indices for surface integrity directly controlled by tool wear and cutting parameters. In this study, high-feed milling (HFM) of a pocket on test samples made of DIN 1.2344 ESR mould steel with 55 HRc hardness was carried out on the CNC vertical milling machine. Three different cutting speeds and five different feed rates were used. At the end of the machining, tool wear was measured using a microscope. Subsequently, X-ray diffraction and hole drilling procedures were used to quantify residual stresses on machined test specimens. The results showed that under cutting conditions, the highest tensile residual stress was attained at f z = 0.78 mm·tooth−1, v = 127.58 m·min−1, and the highest compressive residual stress at f z = 0.5 mm·tooth−1, v = 127.58 m·min−1, on the workpiece surface. The most suitable cutting parameters were reported as f z = 0.63 mm·tooth−1 and v = 70 m·min−1 cutting speed when tool wear and residual stresses are considered together.

Cutting Performance and Wear Behavior of Self‐Developed Silicon Nitride Ceramic End Mills with Optimized Structure for High‐Speed Machining of GH4099

Ceramic tool materials possess a wide range of potential in machining nickel‐based superalloys due to their superior wear resistance, high‐temperature hardness, and strong chemical stability. Herein, a structural optimization scheme of self‐developed silicon nitride ceramic end mill based on stiffness enhancement and performance improvement is proposed, and the key geometric angular parameters scope of the self‐developed ceramic end mills are prioritized via the finite‐element simulation method. Through precision grinding manufacturing and sandblasting pretreatment, the cutting performance and tool wear behavior of three optimized self‐developed silicon nitride ceramic end mills (called S4‐1, S4‐2, S4‐3 respectively) are comprehensively analyzed in comparison, including cutting force, milling temperature, surface quality, and tool life. The results indicate that the cutting force and cutting temperature of all the optimized ceramic end mills are effectively restrained compared with the nonoptimized ceramic tool(S4), and the final workpiece surface roughness is significantly reduced. Further, better surface quality can be obtained by optimized ceramic mills. In terms of tool life, ceramic end mill with optimized construction in best can be increased by up to 1.9 times. The wear mechanism and pattern of the three optimized ceramic milling tools are similar, which is adhesive wear, diffusion wear, and notch wear. Overall, the effectiveness of the optimization scheme for ceramic end mill is successfully verified.

Defocus compensation scheme for femtosecond laser direct writing of large-area non-periodic micro-structures

The optical path error, the position-independent geometric error, and the form and position tolerance of the substrate will lead to position deviations of the laser focus resulting in the inconsistency of the large area micro-structure and limiting the processing range of the femtosecond laser fabrication platform. To realize continuous defocus compensation along the processing trajectory, an autofocus scheme consisting of an optimized depth from focus (DFF) method based on grid division and the bilinear interpolation algorithm is proposed in this paper. The optimized DFF method includes the Laplace-DWT evaluation function combining the advantages of spatial domain and frequency domain sharpness evaluation function, an adaptive focusing window selection method, and an adaptive step length three-step hill-climbing search method. The optimized DFF method was used to obtain the best focus position of each grid point. Compared with the traditional DFF method, the optimized algorithm has higher focusing precision and avoids the disadvantage of time-consuming focusing. Then, to compensate for interpolating points of the processing trajectory, the bilinear interpolation algorithm was introduced to achieve online focusing during two-photon lithography processing. Finally, the feasibility and effectiveness of the auto-focusing scheme were validated by experiments. Through defocus compensation, the sharpness evaluation value of the focus image on the processing trajectory improved by 90%, which indicated the successful focus of the laser beam on the workpiece surface. Moreover, a high-precision and large-area encoded micro-polarizer array with consistent structure were fabricated successfully. This paper provides a simple way to identify and compensate the defocus errors online with high accuracy and efficiency. The proposed method can improve the machining accuracy and quality of the femtosecond laser direct writing.

Establishment and experimental verification of a three-dimensional finite element model for residual stress in surface processing of Inconel 718 alloy by laser cladding

The local load and residual stress changes of conventional forged Inconel 718 alloy can be simulated in a two-dimensional (2D) cutting simulation model, but the type and distribution of global residual stress field of the alloy cannot be predicted during laser cladding layer cutting. To address the shortcomings of conventional 2D cutting simulation models for forging Inconel 718 alloy, this paper proposed a 3D closed-loop finite element model, and taking the dry-side milling process of Inconel 718 alloy laser cladding layer as an example, the generation mechanism and distribution of residual stress are predicted during the machining process. Further testing of surface, near-surface, and subsurface residual stresses was conducted to analyze the specific distribution of residual stresses in the workpiece. The results indicated that the uneven distribution of cutting stress and temperature on the workpiece had a significant non-stationary thermal-mechanical effect on the surface of the machined workpiece; the distribution of surface residual stress was uneven, with the significant tensile residual stress at the workpiece boundary. As the depth increases, the influence of mechanical effects dominated, and the compressive residual stress was generated on the subsurface of the workpiece. Residual stress testing was conducted on the surface/near-surface, and the experimental results were consistent with the simulation results of the closed-loop simulation model. In the subsurface, residual stress showed a similar trend of change. This study compensated for the shortcomings of conventional finite element simulation and provided the reference value for the application of three-dimensional finite element simulation in laser cladding materials.

A Study on the Influence of Process Parameters on the Workpiece Surface Quality in the Cutting of Hard and Brittle Materials with Trepanning Drill.

Hard and brittle materials have excellent physical and mechanical properties and are widely used in the fields of microelectronics and optoelectronics. However, due to their high hardness and brittleness, the machining quality of a workpiece struggles to meet the requirements of practical applications. In order to improve the surface quality of deep-hole machining of hard and brittle materials, this article analyzes the formation mechanism of surface roughness and the exit-chipping width during the drilling machining of hard and brittle materials and establishes a mathematical prediction model for the surface roughness and the exit-chipping width of hard and brittle materials using a trepanning cutter. The experimental study on K9 optical glass machining shows that the surface roughness of the workpiece and the exit-chipping width increase with the increase in feed rate, and decrease with the increase in rotational speed. Through comparison and verification between theoretical and experimental values, the average errors of workpiece surface roughness and the exit-chipping width are 13.15% and 6.73%, respectively. This article analyzes the reasons for the errors. The results indicate that the theoretical model proposed in this article can be used to predict the surface roughness and the exit-chipping width of hard and brittle materials processed under the same conditions, providing a theoretical basis to optimize process parameters to improve the surface quality of the workpiece.

Pneumatic rotary nozzle structure optimization design and airflow characteristics analysis

In this paper, the impact jet field between the pneumatic nozzle and the workpiece surface is simulated by the computational fluid dynamics method, and the influence law of the nozzle structure parameters on the jet performance is obtained by combining the response surface method (RSM), so as to improve the dust removal effect of the pneumatic nozzle. Firstly, the nozzle impact jet field calculation model was established, and the experimental platform of wind speed and volume measurement was built to verify the accuracy of the numerical calculation model and to simulate and analyze the jet field distribution characteristics of the nozzle under rotating working conditions. Then combined with the Box-Behnken Design (BBD) method, a response surface regression model with nozzle inlet radius ( R1), cylindrical section length ( L), and cone angle ( A) as design variables and nozzle jet fixed point (20 mm) flow rate as the target variable was established to find the optimal combination of nozzle characteristics parameters. The results show that the optimized nozzle characteristics parameters using RSM can effectively improve the nozzle jet performance, the optimized jet flow rate increased by 8.38%, and can be more effective in dust removal; jet pressure on the workpiece surface decreases as the nozzle incidence angle increases; in the speed range of 400–1200 r/min, the pressure change caused by the jet on the wall surface is small, and the flow rate is relatively stable.

ВЕРОЯТНОСТНАЯ МОДЕЛЬ ИЗМЕНЕНИЯ МИКРОГЕОМЕТРИИ ПРИ МНОГОПЕРЕХОДНОМ ФРЕЗЕРОВАНИИ ЦВЕТНЫХ СПЛАВОВ

The results of experimental studies of microgeometric characteristics of flat surfaces of non-ferrous alloy workpieces processed at the transitions of roughing, finishing and fine contour milling are presented. It is shown that the results of processing in terms of the quality of the treated surface and in terms of the uniformity of the results obtained depend significantly on the physical and mechanical properties of the material being processed. Probabilistic quality tables for milling workpieces from Ti95Al5 and Al94Mg6 alloys are presented.

Effects of thermo-chemical treatment and grinding process of external cylindrical surfaces on residual stresses in 13CrMo4-5 steel

This paper presents a study aimed at determining the effect of the carburizing treatment process and the subsequent grinding process on the residual stresses occurring in ring-shaped specimens made of 13CrMo4-5 steel.During the tests, vacuum carburizing was used, achieving an effective case depth ECD = 0.5 mm. Subsequently, the cylindrical outer surfaces of the samples were ground by conventional plunge grinding and with innovative kinematics using a test stand based on a conventional flat-surface grinding machine. As part of the study, microhardness and residual stresses were measured before and after grinding. Measurements were carried out to a depth of 1 mm. The main component of the stand is an original special device that allows the cylindrical specimen to be clamped. Then the angle between its axis of rotation and the axis of rotation of the grinding wheel is set with respect to the plane of the grinding machine’s magnetic table. In the described tests, the axis of rotation of the cylindrical specimen was deviated from its original position by 15 and set at an angle of 75 to the axis of rotation of the grinding wheel. The specimens were ground with a grinding wheel of noble electro-corundum marked 38A60K8V. In both kinematic cases of the grinding process, a machining allowance of 0.01 mm was removed.Grinding using innovative kinematics did not cause any significant changes in the microhardness distribution, either for vacuum or conventional carburizing. In addition, residual stress measurements using the Dawidenkov-Sachs method showed that innovative grinding enables a more favourable distribution than those obtained after conventional plunge grinding.Further research will focus on, among others, selecting the angular settings of the workpiece axes relative to the grinding wheel axes depending on their dimensions. Grinding guidelines should include coverage ratio, infeed value, grinding time, and peripheral speeds. In addition, the plan for future research includes measuring the components of the grinding force and the geometric structure of the surface.Grinding process is a crucial stage of steel treatment in almost every industrial branch. In sustainable manufacturing, it is extremely important to produce high-quality items while reducing the cost of manufacturing and taking care of the environment and workers’ health.The proposed test stand, together with the authors’ device, makes it possible to conduct machining of the external surfaces of cylindrical workpieces on a flat surface grinder. In this case, the innovation of the grinding process consists of the non-parallel alignment of the cylindrical rotational axis of the specimen and the rotational axis of the grinding wheel with respect to the plane of the magnetic grinding table.

Mechanical analysis and machinability evaluation of a new EDM-turning hybrid machining process

This study developed an accurate electrical discharge-assisted turning (EDAT) technique for Ti–6Al–4 V alloy and a precise EDAT cutting force prediction model considering theoretical multi-physics fields with metallurgical transformation. A heat-fluid coupled model of multi-pulse discharge in the EDAT process was developed to obtain the thickness of the removal layer (RL) and modified layer (ML) together with the temperature field of the cutting layer. Subsequently, the shear flow stresses under different machining parameters were obtained using the oblique cutting and flow softening constitutive models. Within the cutting layer, the pure thermal softening effect reduces the flow stresses by more than 25% in the unmodified matrix layer (UML) and by more than 60% in the ML, which is dominated by the metallurgical transformation softening (MTS) effect. Finally, the cutting force model of EDAT under multi-physical fields was established and the accuracy was verified by relevant experiments. The results showed that the increase in discharge number accelerated the rise of workpiece surface temperatures, and the small cutting parameters were favorable to the machining performance of the EDAT. The MTS effect significantly reduces cutting forces while improving the quality of the machined surface.