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Variable cross-section spherical groove structure had high surface hardness and complex 3D shape. ECM had better technical and economic advantages, but the processing accuracy and processing stability were affected by the flow field obviously. In order to improve the uniformity of the electrolyte flow field, the influences of the electrolyte flow mode and channel structure on the flow field distribution were discussed based on the flow field simulation analysis, and the ECM experiments were carried out. The simulation and test results show that the zonal liquid flow in directional channel is conducive to improving the stability of the flow field and the consistency of the flow rate distribution, which may improve the processing stability. Optimization of the inlet and outlet flow channel structures may further improve the surface quality of the spherical groove, which may meet the requirements of machining stability and machining accuracy. [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Flow Drill Screw (FDS) is the main connection method ol single side connection in multi-material vehicle body, and machining pilot hole in upper plate is the common auxiliary connection method. Taking HC340/590DP high-strength steel and 6063-T6 extruded aluminum as the research objects, the ellects ol the thickness ol the upper plate and the size ol the pilot hole on the shear strength and failure mode ol the joint were studied by shear tensile test. The results show that when the thickness ol the upper steel plate was 0. 8 mm and the diameter ol the pilot hole was 5. 5 mm, the shear failure load and energy absorption capacity of the FDS joints were greatly reduced. When the diameter ol the pilot hole was smaller than 5. 5 mm, the energy absorption capacity ol the FDS joints decreased with the increase ol the t hickness ol the upper st eel plate under the same diameter ol the pilot hole. Moreover, the ratio ol the thickness ol the upper steel plate to the diameter ol the pilot hole(/) allect the failure mode and mechanical properties ol the FDS joint. When f was greater than 0. 27, the failure mode of the FDS joints was screw fracture and the shear failure load was basically unchanged. When f was less than 0. 27, the failure mode ol FDS joint was upper plate tearing, and the shear failure load increased with the increase of f value. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To study the surface integrity of the stainless steel closed integral bling in abrasive flow machining, single factor tests of processing time, processing pressure and abrasive mesh size are carried out on the stainless steel samples prepared by electrical discharge machining, and the influence of three factors on the surface integrity after machining is investigated. The surface roughness value Ra decreases with the increase of processing time, from 1.459 μm at the initial time to 0.193 μm at 60 min. The surface roughness decreases at a slower and slower rate, and finally tends to stabilize. The recast layer is effectively removed by abrasive flow machining, and the microhardness decreases from 450~950 HV to 270~350 HV after machining, and the distribution uniformity is improved. The microhardness decreases with the increase of processing time, and some work hardening occurs. The residual stress changes from tensile stress to compressive stress after abrasive flow machining with different mesh numbers of abrasives. With the increase of processing time and pressure, the smoother the sample surface is, the better the polishing effect will be. [ABSTRACT FROM AUTHOR]

Due to the large workspace, flexible posture, high configurability and low cost, industrial robots are widely used in various fields such as transportation, assembly, spraying, welding, etc. Because of the low precision of robot end track and the large fluctuation at low speed, it is rarely used in the field of electrochemical machining. According to the characteristics of low speed and high trajectory accuracy of electrochemical machining, a quadrant method is proposed to set the working area of the electrochemical machining robot and the dynamic optimization function of the electrochemical machining robot is establisbed. The third-generation non-dominated genetic algorithm NSGA-Ⅲ is used to solve the optimal Pareto solution set of each design parameter. The dynamic performance test is carried out through simulation and experiment. The results show that within the set working area, the straight track accuracy of the electrochemical machining robot can reach 0.073 mm, the arc trajectory accuracy can reach 0.145 mm, and the trajectory accuracy under low-speed conditions is nearly 10 times higher than that of traditional industrial robots. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the problems existing in through-mask electrochemical machining (TMECM) of microporous array structure i.e. poor localization and inaccurate diameter and insufficient depth of micropores, it was proposed to carry out TMECM with the assistance of SiC particles (the process was noted as PA-TMECM). The effects of diameter and mass fraction of SiC particles and flow rate of electrolyte on the fabrication of microporous array structure were studied, and the mechanism of PA-TMECM was discussed. The experimental results showed that it had the best machining localization with an etching factor of 3.52 for PA-TMECM with 6 g/L of SiC particles (40 μm in diameter) at an electrolyte flow rate of 3 000 mL/min. The electrolytic products on the surface of anode can be removed efficiently due to the continuous and highly frequent impact of the particles onto the anode surface during PA-TMECM, not only increasing the etching depth of micropores, but also limiting the lateral corrosion of micropores, finally improving the machinning localization. [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aero-engine casings are important connecting and bearing components in aero-engine. Because of their complex structures, weak rigidity and difficult-to-machining materials, there are many manufacturing problems remaining for casing part such as serious machining deformation and poor accuracy of wall thickness, which has become a bottleneck restricting the development and production of new aero-engines. Aiming at this requirement, we propose a new method named counter-rotating electrochemical machining (CRECM). During CRECM, a revolving cathode tool is used, and the anode workpiece and cathode tool rotate oppositely at the same rotational speed. As the material is dissolved accurately layer by layer in CRECM, the large thin-walled casing part can be machined precisely without deformation. The fundamental scientific problems involved in CRECM such as the anode shaping rule, the pulse dynamic dissolution mechanism of difficult-to-cut materials and the distribution characteristics of electrolyte flow field are revealed. The key technologies such as cathode tool design, pitting inhibition of titanium alloy and optimization design of electrolyte flow field are broken through. Moreover, a large-scale CRECM machine with independent intellectual property rights has been developed, and large thin-wall casing parts are fabricated efficiently and precisely. The research provides important technical support for the development and production of new aero-engines. [ABSTRACT FROM AUTHOR]

Electrolyte plasma polishing, an environmentally friendly process, was adopted to treat 316L stainless steel jewelry. The polishing effectiveness was evaluated by laser confocal microscopy and spectrophotometry. The results showed that the surface roughness of workpiece could be effectively reduced and its surface brightness could be increased by increasing the initial temperature of electrolyte and pre-polishing it before electrolyte plasma polishing. In order to gain excellent surface quality on 316L stainless steel jewelry, the initial temperature of electrolyte should be 75 °C at least, and it'd better to polish it with 400# or finer sandpaper. The polishing time could be estimated according to the surface area of jewelry and the polishing rate of 0.37 min/cm². [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Electrochemical machining (ECM) was conducted on TC17 titanium alloy followed by vibration finishing (VF). The surface integrity of TC17 titanium alloy treated after ECM and VF were analyzed by using scanning electron microscope, three-dimensional white light interferometer, and residual stress analyzer. The tensile and vibration fatigue properties of TC17 titanium alloy treated by different methods was also tested at room temperature. The results showed that the surface of TC17 titanium alloy was smooth with a much lower roughness and a relatively high compressive residual stress after ECM and VF. The grain orientation of TC17 titanium alloy was almost unaffected due to the slight plastic deformation of its surface. The TC17 titanium alloy treated by ECM and VF showed an equivalent tensile strength at room temperature to the one treated by ECM, while the vibration fatigue property of the former at room temperature was better than that of the later. [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the surface wear resistance of materials, the effects of surface morphology generated by different electrochemical machining parameters on the tribological properties of materials were investigated. Electrochemical tests were carried out on 45 steel specimens to study the effects of electrolysis time on pit morphology and surface morphology on the friction properties of 45 steel specimens, as well as the effect of surface morphology on the friction properties of 45 steel specimens under dry friction and lack of oil lubrication. The results show that the surface of the specimen becomes smooth after electrochemical machining. There are randomly distributed circular pits, and the distribution density of the circular pits increases with the increase of electrochemical machining time. The wear volume of specimens under two friction conditions has the same variation trend, which firstly decreases and then gradually increases with the increase of electrochemical machining time. When 20% sodium chloride is used as electrolyte, the surface pit diameter increases with the increase of electrolysis time, but too long electrolysis time will lead to the deterioration of surface quality. It can be concluded from the wear volume and friction coefficient obtained from the test that the best test group is the pit diameter range of 50 µm to 80 µm and the depth range of 5 µm to 10 µm, and compared with 45 steel specimens without electrolytic treatment, the wear volume decreases by 13% and 14% under dry friction and lack of oil lubrication condition, respectively. In the mixed electrolytic solution of 20% sodium chloride and 10% sodium hypochlorite, the optimal 45 steel specimen is obtained in the electrolysis time of 180 s, and the wear volume is reduced by 33% compared with the 45 steel specimen without electrolytic treatment. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For turbine disk slots of high-end power equipment such as aero engines and gas turbines, the machining technologies were analyzed from two aspects of mechanical machining (e.g., broaching, milling, grinding) and nontraditional machining (e.g., wire electric discharge machining and wire electrochemical machining), respectively. The development current situations were systematically explained from the viewpoints of design and application of tools, evaluation and control of machining quality. The important achievements of the research work in this field at home and abroad were also introduced. Finally, the development trends were generalized prospectively. [ABSTRACT FROM AUTHOR]

A method of machining titanium-aluminum intermetallic compounds TiAl 45XD was proposed by combining WEDM and WECM. During the WECM, the recast layers were removed by first "pass", and the possible intergranular corrosions were eliminated by second "pass". The electrochemical characteristics of the cast TiAl 45XD mechanical polished surfaces and the WEDM surfaces were studied respectively. It is found that both of the surfaces have passivation in water-based solutions (WBS), and there are almost no obvious passivation in glycol-based solutions (GBS). Compared with the WBS, both of the surfaces are more susceptible to corrosion in the GBS, and the WEDM surfaces are more corroded than that of the polished surfaces. Then the effects of feed speed and cutting depth on surface integrity were analyzed, the testing results show that when the feed speed of first "pass" is as 25 µm/s and the cutting depth is as 20 µm, the feed speed of second "pass" is as 60 µm/s and the cutting depth is as 0, the recast layers are removed, the intergranular corrosions are eliminated, the surface roughness value is reduced to 1.6 µm, and the average feed speed is as 17.65 µm/s, which proves that the use of WEDM for rough forming, WECM with GBS for trimming is a feasible method for machining straight-grained titanium-aluminum intermetallic compound components with high surface integrity. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Dalian University of Technology / Dalian Ligong Daxue Xuebao is the property of Journal of Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An AS-EMM method was presented to process the microstructures with different array shapes on planes and cylindrical metal surfaces. Comparisons were carried out between AS-EMM and EMM by analyzing the machining accuracy, surface quality and friction properties of the micro-texture. The results show that the eroded dimple aspect ratios of planes and cylinder pairs are increased by 45.6% and 25.8% respectively which may improve the dissolution localization and the machining precision by AS-EMM. Besides, the friction-wear test results express the 13.6% and 16.2% reduction respectively in average coefficient of friction values on different pairs by AS-EMM. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangdong University of Technology is the property of Journal of Guangdong University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objectives] In order to further improve the fuel efficiency of diesel engines and reduce the cost of maintenance, a research about using electrochemical machining(ECM)technology to remove sharp edges and burrs at the intersection of cross-holes in fuel injection body was carried out. [Methods] Based on COMSOL Multiphysics the model of ECM processing was established. The influence of the change rule of radius caused by cathode structure was studied. Meanwhile, the cathode structure was optimized. The transition arc radio obtained by experiment and simulation were also compared and analyzed. [Results] Finally sharp edges and burrs at intersecting holes were removed, and the size of radius obtained by ECM was within R=(2±0.2)mm. The experimental results showed that the finite element model of ECM processing predicted the size of radius accurately. Also the finite element model of ECM processing guided the optimal design of cathode and the selection of process parameters. [Conclusions] The optimized cathode can accurately control the radius of the transition arc at the intersection of cross-holes to R=(2±0.2)mm. [ABSTRACT FROM AUTHOR]

For the complex physical change and poor observability of the radial ultrasound rolling eletrochemical micromachining (RUR-EMM) gap physics field, the coupling effect of multi-physical field in machining gap is studied based on the numerical simulation method. A multi-field coupling theory model of electric field, two-phase flow field, temperature field and sound field in machining gap is established. Based on the proposed model, the variation rule of multi-field coupling interaction and the forming rule of micro dimple under multi-field coupling are obtained by numerical simulation method. Results show that the electrolyte in the gap flows into and out of the machining zone with vibration frequency of 20 kHz, amplitude of 10 μm, machining gap of 50 μm, cathode rotating angular velocity of 0.6°/s, and electrode conductivity of 7.9 S/m. The current density periodically changes with vibration cycle, and the temperature of electrolyte increases with the combined action of ultrasonic vibration and electrochemical reaction. Compared with rolling electrochemical micromachining (R-EMM), the gap temperature and current density of RUR-EMM are increased by 3.63% and 1.45 times, respectively, and the dimple depth of RUR-EMM is increased by 14.21%. This is because the pulsating flow field in the gap promotes the discharge of products effectively. The experimental results of micro-dimple machining verify the correctness of the theoretical model. The error between the simulated and experimental machining depths is less than 17.07%. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The integral impeller made of difficult to machine materials is widely used in the aviation field. The traditional machining has the problems of fast tool wear and low machining efficiency. In this paper, a large cutting depth five axis numerical control electrochemical milling pre-processing method is proposed for a certain type of complex integral impeller. Through the design of the conical spiral blade cathode, the flow field distribution at the outlet of single and double spiral blades with different rotation angles is analyzed，and the distribution of the pressure and flow velocity at the outlet of the single spiral blade cathode with rotation angle of 720° is uniform. At the same time, the experiment of NC electrochemical milling with large cutting depth is carried out. The results show that: Within the range of selected process parameters, the machining balance gap and feed speed increase with the increase of machining voltage ； The lower electrolyte temperature is conducive to the realization of small gap machining, which can significantly improve the machining accuracy； The spindle speed reaches 1 500 r/min, which has little impact on the machining speed. The results show that the maximum cutting depth can reach 65 mm, and the margin error can be controlled within °.5 mm, which improves the machining efficiency of the whole impeller. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Hebei University of Science & Technology is the property of Hebei University of Science & Technology, Journal of Hebei University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The design of flow field is an important part of preparing the cathode and device in the electrochemical machining of cochlear channel of closed integral structure. The models of the forward feed device and reverse feed device are established based on UG, of which inlet area is about twice as much as outlet area, respectively, and their gap flow fields are simulated based on COMSOL Multiphysics. The difference between these gap flow fields formed by the forward feed and reverse feed at the same electrolyte inlet pressure is analyzed from its streamline pattern, velocity and pressure nephograms. The results show that the flow velocity of the end gap and the side gap in the reverse feed is higher than that in the forward feed, and the flow field of the reverse feed is more uniform. The reverse feed devices are used in the experiment, the machining process is smooth without spark and short circuit. [ABSTRACT FROM AUTHOR]

Electrochemical machining (ECM) is one of the important technologies in production of aeroengine blisk. The cathode modification is an important part of the processing technology. In order to improve the modification precision of cathode, a new method based on normal direction of constant sampling points is presented. The 1-D coordinate system along the normal direction of sampling points is established. The basic cathode surface, machining error and correction value are calculated in the coordinate system. The position deviation of machining error and correction value is eliminated by using the new method. In order to test the validity of the cathode modification method, experimental investigations of blisk processing are carried out by using a self-designed blisk ECM system. The machining samples are detected by the three-coordinate measuring machine. After one modification of cathode, the accuracy of ECM blade is increased from 0.25 mm to 0.04 mm. Experimental results verify the feasibility and effectiveness of the new cathode modification method. [ABSTRACT FROM AUTHOR]

The three-dimensional multiphase flow model and indirect multiphysics model (including thermoelectric coupling model and thermal-fluid coupling model) are developed to describe the variations of electric field, flow field and temperature in the electrochemical machining gap. The electrochemical machining of the internal spiral hole is simulated. Simulation results show that the electrolyte velocity is fluctuant and decreasing, and the electrolyte temperature as well as the void fraction of the hydrogen are increasing along the flow direction. According to the variations of temperature and the void fraction of hydrogen, the electric conductivity of electrolyte is studied, which has a main effect on the material removal. The analysis denotes that the electric conductivity of electrolyte increases along the flow direction. As a result, the material removal rate (MRR) decreases along the flow direction which is unfavourable for machining. A method of applying back pressure in the outlet is selected to diminish the variation of electric conductivity of the electrolyte. Finally, experimental verification of the model using an in-house built electrochemical machining system for the internal spiral hole exhibits good correlation with theoretical predictions. [ABSTRACT FROM AUTHOR]

In order to reduce the volatility and heterogeneity of the cathode flow in numerical control electrochemical milling, and improve the accuracy and surface quality of the workpiece in electrolytic machining, a spiral blade cathode structure is proposed. The flow model of the cathode structure is built and simulated by using the standard turbulence model. The simulation results show that the electrolyte flow velocity and pressure distribution are influenced by internal channels with different structures and different technology parameters, therefore the structure of cathode is improved according to the simulation results. Finally, regarding the impeller as the milling object, experiments are carried out at the CNC composite electrolytic milling machining center. The experimental results verify the validity and correctness of the simulation. [ABSTRACT FROM AUTHOR]

In the deep hole electrochemical machining of tubular electrode, the main reason of short circuit is oxidation film layer on the end face of electrode. The morphology and composition of the tool electrode end face processed by unidirectional pulse and bidirectional pulse are analyzed using scanning electron microscopy (SEM), and the formation mechanism of oxide film layer is also analyzed. The results show that the continuous loose oxidation film layer is formed on the end face of tubular electrode by using unidirectional pulse, its compositions are mainly the oxides of C and Si, the main reason of forming oxide film layer is the adsorption effect of tool electrode, using the right proportion of positive and negative pulse can inhibit the forming of oxidation film and the formed oxidation film layer could be removed efficiently, and the stability of electrochemical machining deep holes can be improved apparently. [ABSTRACT FROM AUTHOR]

For the difficult prediction and control of the forming size during electrochemical machining (ECM), the three-dimensional simulation and verification experiments of the gas-liquid two-phase turbulent flow in the inter-electrode gap are performed by using Fluent software with mixture model, extended SIMPLEC algorithm and standard k-ε turbulence model. A spiral deep small hole is used as the processing subject in ECM for simulation and experiment. The flow characteristic in the inter-electrode gap is revealed. The results show that the velocity of the mixture in the inter-electrode gap has an important effect on the discharge of the dissolution products. Flow speed decreases and the machining stability becomes worse with the increase in hole depth. The gas volume fraction increases and the electrical conductivity decreases along the direction of the electrolyte flow, resulting in the non-uniform of the machining size of the workpiece. Furthermore, a back pressure on the outlet could reduce the non-uniform. The shape of cathode influences the flow-field characteristics. The 'dead zone', short circuit and spark could be avoided by properly designing the cathode shape. [ABSTRACT FROM AUTHOR]

In order to realize the processing accuracy of the deep hole on hard-cutting alloys in the pulse electrochemical machining, a dynamic math model for the linear removal rate is established and the effect of process parameters is analyzed also. The effects of pulse width, tool feed speed and insulating layer on the tool are studied experimentally. The experiment results show that the longer pulse width, higher feed speed and insulation of all outside surface of tool can improve the processing accuracy of the deep hole. [ABSTRACT FROM AUTHOR]

In order to improve the process of non-traditional micro machining, a composite technology with solid tool was proposed. Several non-traditional micro-machining processes were analyzed and their common features were found out. The micro electro-discharge machining (EDM), micro ultrasonic machining (USM) and micro electrochemical machining (ECM) were combined in the same system. The module design was used for this system. The basic module was developed, and a video microscopic subsystem was equipped in the system. Then, Φ5 µ, micro rods, Φ 6µm micro holes, and microstructures with complicated profile were machined by micro EDM; the micro holes with aspect ratio larger than 25 were machined by EDM with USM in inversion installing; Φ13 µm micro holes were drilled by micro USM; and Φ100 µm micro holes were machined with micro ECM. This kind of combination expands the range of non-traditional micro machining and improves the processing efficiency. [ABSTRACT FROM AUTHOR]

Based on the platform of Unigraphics (UG), with the secondary development tool UG/Open API and the method of dynamic assemble, a program is designed to simulate the process of numerically controlled electrochemical machining (NC-ECM). The NC track is checked, the gap between workpiece and cathode is estimated, and interference is detected. Then the simulation on the machining of material removal is completed, and a machined model is produced. The study provides a basis for the modification of NC code and cathode design, and for the machining. The key points to develop the program are emphatically discussed, and test machining is carried out. [ABSTRACT FROM AUTHOR]

A method of designing cathode in electrochemical machining by numerical simulation was proposed based on the analysis of problems existed in traditional design methods. The course of designing cathode and the method of determining the initial cathode shape by simulation were given. The mathematical model for ECM was established, the finite element method was used to calculate the electrical field and flow field. Then a set of tool software for designing cathode was developed and applied to the practice. Results demonstrate that the proposed method can effectively improve the design accuracy, reduce the number of trial and error cycles and shorten the periods of cathode design. [ABSTRACT FROM AUTHOR]

Taking ECM GH4169 honeycomb ring as test background, the relationship between the paralled gap and two main processing parameters, the voltage and duty ratio is studied. Based on statistical probability and regression analysis principle, a parallel gap prediction model of ECM high-temperature alloy GH4169 is established, so micro-electrochemical machining technological rules conforming to actual production situation are obtained. [ABSTRACT FROM AUTHOR]