Study on the Shaping Law of Precision Numerical Controlled Electrochemical Contour Evolution Machining

2008 ◽  
Vol 375-376 ◽  
pp. 72-76 ◽  
Author(s):  
Min Kang ◽  
Jia Wen Xu

Numerical Controlled Electrochemical Contour Evolution Machining (NC-ECCEM) is one of the most important development in Electrochemical Machining (ECM). In order to improve the machining accuracy of NC-ECCEM technology, the research works on precision NC-ECCEM technology are needed, and especially the study on its shaping law is significant for improving the machining accuracy of workpiece profile. In this paper, the shaping law of machining the planar surface by use of a kind of inner-spraying cathode with rectangle section was studied. First, the basic differential equations of shaping law in the case of cathode movement were established. Then, considering the structure of the cathode, the methods for calculating the side gap in machining the planar surface was given. Finally, the experiments of machining the planar surface were carried out. Experiments show that the calculated side gaps are bigger than the actual values, but the change trend of calculated side gaps with machining process parameters is coincident with the actual side gap change trend.

2011 ◽  
Vol 204-210 ◽  
pp. 1830-1834
Author(s):  
Zhao Long Li ◽  
Shi Chun Di

The method of machining deep hole on Ni-base alloy which can tolerant high temperature by pulse electrochemical machining has been proposed in this paper. Five technical parameters are discussed on the effect of mass removal rate of machining process. Establish a dynamic math model, and analyze the effect of process parameters on the mass material removal rate of deep small holes. Machining accuracy of deep small holes was analyzed.


2011 ◽  
Vol 55-57 ◽  
pp. 1275-1280 ◽  
Author(s):  
Jian Min Wu ◽  
Jia Wen Xu

While the surface of integral impeller blade was electrochemically machined, cathode cannot rotate in accordance with other movement axes, which results in nonuniformity in velocity of electrolyte and normal direction of the machining blade surface, thereby causing inaccuracy in the machined blade surface. In order to solve this problem, the shaping law was studied in Electrochemical Finish Machining. Then relative positions between cathode slot and blade surface were analyzed during the process of Electrochemical Machining (ECM). Three parameters, namely feed direction, feed velocity and initial machining inter-electrode gap, were adjusted to conduct the fundamental experiments when direction of cathode slot was changed. Afterwards machining accuracy as well as surface quality of workpiece was analyzed. Finally according to experimental results, direction of cathode slot was determined practically in electrochemical machining process and the integral impeller blades meeting the requirement were electrochemically machined.


2010 ◽  
Vol 97-101 ◽  
pp. 3583-3586 ◽  
Author(s):  
Zhi Yong Li ◽  
Hua Ji

Cathode design is a difficult problem must be faced and solved in electrochemical machining (ECM). In ECM process, various parameters, such as applied voltage, current density, gap distribution, machining rate and electrolyte composition and concentration, can affect ECM machining process and therefore cathode design. Among all these machining parameters, gap distribution is the most vital. Regard some type of aero-engine compressor blade as research object, this paper concentrates on the effects of the normal gap distribution of 2-dimension and 3-dimension on cathode design based on the cathode design method of , moreover the errors between two and three dimension normal gap also can be compared and analyzed in detail. To verify the accuracy of the designed cathode, the machining experiments were conducted on an industrial scale ECM machine and the experimental results demonstrates that the cathode designed utilizing 3-dimension normal gap exhibits more machining accuracy and therefore valuable.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
T. Praveena Gopinath ◽  
J. Prasanna ◽  
C. Chandrasekhara Sastry ◽  
Sandeep Patil

Abstract An attempt has been made to study the influence of magnetic field on the micro hole machining of Ti-6Al-4V titanium alloy using electrochemical micromachining (ECMM) process. The presence of magneto hydro dynamics (MHD) is accomplished with the aid of external magnetic field (neodymium magnets) in order to improve the machining accuracy and the performance characteristics of ECMM. Close to ideal solution for magnetic and nonmagnetic field ECMM process, the parameters used are as follows: concentration electrolyte of 15 g/l; peak current of 1.35 A; pulse on time of 400 s; and duty factor of 0.5. An improvement of 11.91–52.43% and 23.51–129.68% in material removal rate (MRR) and 6.03–21.47% and 18.32–33.09% in overcut (OC) is observed in ECMM of titanium alloy under the influence of attraction and repulsion magnetic field, respectively, in correlation with nonmagnetic field ECMM process. A 55.34% surface roughness factor reduction is ascertained in the hole profile in magnetic field-ECMM in correlation with electrochemical machined titanium alloy under nonmagnetic field environment. No machining related stress is induced in the titanium alloy, even though environment of electrochemical machining process has been enhanced with the presence of magnetic field. A slight surge in the compressive residual factor, aids in surge of passivation potential of titanium alloy, resulting in higher resistance to outside environment.


Author(s):  
Sajjad Beigmoradi ◽  
Mehrdad Vahdati

Polymers have gained the attention of manufacturers due to their significant advantages such as low density, high corrosion resistance, and high humidity resistance. Producing high-precision polymeric components is one the most challenging issues especially in fabricating complex or micro-scale systems. Some of the machining techniques such as electro discharge machining (EDM) and electrochemical machining (ECM) cannot be employed for machining the non-conductive parts. Using abrasive particles is one of the best options for machining these types of materials. In this work, the capability of the acoustic energy for machining polyamide (PA) workpieces is studied. To this end, an experimental setup is installed and design of experiment (DoE) algorithm is employed to survey the effect of process parameters on surface roughness. Three parameters at three levels are considered as the effective factors of the process and the sensitivity of the surface roughness on the process factors is investigated. In the next step, a hybrid finite element/boundary element approach was used to discuss the relation of process parameters to the vibrational characteristics of the container, then the mechanism of the process was investigated employing the discrete element method. Finally, the surface topology of the optimal workpiece before and after the process was presented and compared. It was observed that acoustic energy can be considered as a vibration source of the container’s floor to provide kinetic energy for machining PA parts on the nano-metric scale. Moreover, it was found that the initial roughness of the workpiece and the chosen parameters play a crucial role in the machining process. Experimental results show that in this technique by selecting appropriate process factors the surface roughness can be reduced up to 50%.


Author(s):  
Lingguo Yu ◽  
Dong Zhu ◽  
Yujun Yang ◽  
Jibin Zhao

Cathode design plays an important role in the electrochemical machining of aero engine blades and is a core issue influencing machining accuracy. Precision electrochemical machining of the leading edge of a twisted blade is particularly difficult. To improve the electrochemical machining accuracy of the leading edge, this article deals with cathode design by optimizing the design plane based on the three-dimensional potential distribution in the inter-electrode gap. A mathematical model is established according to the electrochemical machining shaping law, and the formation of the blade leading edge is simulated using ANSYS. The simulation results show that the blade leading-edge profile obtained with the optimized planar cathode is more consistent with the blade model profile. The optimized planar cathode and a non-optimized planar cathode are designed and a series of corresponding electrochemical machining experiments is carried out. The experiments show that the electrochemical machining process is stable and that the surface quality near the leading edge of the samples is slightly better than that of the body surface. Compared with the non-optimized planar cathode, the allowance difference at the leading-edge vertex is decreased by 0.062 mm. Using the optimized planar cathode allows fabrication of a workpiece whose shape is similar to that of the designed twisted blade.


Author(s):  
Feng Wang ◽  
Jianshe Zhao ◽  
Yanming Lv ◽  
Zhenwen Yang ◽  
Weimin Gan ◽  
...  

Electrochemical machining has the advantage of being free of cathode loss, thermal stress, and residual stress, and is suitable for high precision machining of metal structures. Localization of anodic dissolution can be significantly improved by the side-wall insulation of the cathode. However, for shaped-hole machining, the removal of electrolytic products in the machining gap becomes problematic with the increase of machining depth, which may hinder the machining process. The application of vibration to the cathode in an electrochemical machining is considered an effective approach because the frontal gap is periodically changed by the vibration; therefore, the removal of electrolytic products and the refreshment of electrolyte are facilitated. This study is aimed at finding a suitable method for diamond-shaped hole fabrication using electrochemical machining. The influence of vibrating feed, cathode with and without side-wall insulation on the machining stability and accuracy were studied based on the machining system developed in this study. The experimental results reveal that the machining accuracy of the diamond-shaped hole can be improved remarkably by reducing the width of the tool edge. Meanwhile, the machining stability can be improved significantly with a reasonable vibrating feed mode.


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