scholarly journals Investigation on the Electrochemical Micromachining of Micro Through-Hole by Using Micro Helical Electrode

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 118 ◽  
Author(s):  
Baohui Liu ◽  
Hang Zou ◽  
Haixuan Luo ◽  
Xiaoming Yue
Keyword(s):  
Process Parameters ◽  
High Speed ◽  
Pulse Frequency ◽  
Machining Process ◽  
Electrochemical Micromachining ◽  
Good Effect ◽  
Machining Accuracy ◽  
High Speed Rotation ◽  
Helical Electrode ◽  
Through Hole

The instability of machining process caused by the difficulty of the electrolyte refresh in electrochemical micromachining (EMM) of micro through-hole has been an unsolved problem. Thus, this paper investigates the electrochemical micromachining of micro through-hole by using a micro helical electrode combining with the jetting electrolyte. With the help of high-speed rotation of micro helical electrode and its spiral shape, the internal electrolyte can be stirred while the external jetting electrolyte can flow into the hole along the spiral groove to refresh the electrolyte effectively, thereby, improving the machining stability of EMM. Firstly, the influence of the process parameters on the fabrication of micro through-hole in the EMM by using micro helical electrode without non-conductive mask is investigated. Based on the optimization of the process parameters, a micro through-hole with an inlet dimension of 121.6 μm and an outlet dimension of 114.9 μm is obtained successfully. Furthermore, this paper also tries to use the micro helical electrode coated with the non-conductive mask to decrease the bad influence of the stray corrosion attack. It is found that the non-conductive mask coated on the surface of micro helical electrode can improve the machining accuracy significantly under the condition of low pulse frequency (≤1 KHz). However, its good effect on preventing the stray corrosion decreases along with the increase of the pulse frequency.

scholarly journals Flow Field Characteristics and Experimental Research on Inner-Jet Electrochemical Face Grinding of SUS420J2 Stainless Steel

2021 ◽  
Author(s):  
Feng Wang ◽  
Yafeng He ◽  
Xiaokai Wu ◽  
Min Kang
Keyword(s):  
Stainless Steel ◽  
Flow Field ◽  
High Speed ◽  
High Hardness ◽  
Good Prospect ◽  
Matching Effect ◽  
Object A ◽  
Flow Field Characteristics ◽  
High Speed Rotation ◽  
Through Hole

Abstract Electrochemical grinding (ECG) is processed by the combination of dissolution and grinding. It is very suitable for the processing of difficult-to-cut stainless steel, but its processing performance is restricted by the matching effect of dissolution and grinding. In this work, the processing of the torus surfaces of the stainless steel shaver cap was taken as the research object. A flow field model including the through-hole structure and the rotation of the grinding head was proposed to optimize the flow field distribution and promote the uniform dissolution of materials. The flow field simulation results showed that the rotational flow formed by the high-speed rotation prolonged the electrolyte flow path and was not conducive to the discharge of electrolytic products, and the reasonable selection of the diameter and distribution of the through-hole could reduce the velocity difference. The effects of rotational speed, feed rate, and inlet pressure on the flatness and surface roughness of the torus surfaces were experimentally investigated, and a better matching effect of dissolution and grinding was obtained. Moreover, the experimental results showed that the inner-jet ECG had a good prospect in the batch processing of high-hardness stainless steel parts.

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
Keyword(s):  
Differential Equations ◽  
Process Parameters ◽  
Electrochemical Machining ◽  
Machining Process ◽  
Machining Accuracy ◽  
Planar Surface ◽  
Important Development ◽  
Contour Evolution ◽  
Change Trend ◽  
Side Gap

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.

scholarly journals Effect of Process Parameters on the Quality of Laser-Cut Stainless Steel Thin Plates

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1224
Author(s):  
Irene Buj-Corral ◽  
Lluís Costa-Herrero ◽  
Alejandro Domínguez-Fernández
Keyword(s):  
Process Parameters ◽  
Laser Cutting ◽  
Pulse Width ◽  
High Speed ◽  
Linear Models ◽  
Dimensional Accuracy ◽  
Pulse Frequency ◽  
Thin Plates ◽  
Dimensional Error ◽  
Frequency Pulse

At present, laser cutting is currently employed to cut metallic plates, due to their good finish and dimensional quality, as well as because of the flexibility of the process to obtain different shapes. In the present paper, surface roughness, dimensional accuracy, and burr thickness of thin plates of 0.8 mm are studied as functions of different process parameters: pulse frequency, pulse width, and speed. Eight different experiments were performed according to a full 23 factorial design, with two replicates each. Square specimens of 10 mm × 10 mm were cut. Arithmetical mean roughness Ra was measured with a contact roughness meter, and the dimensions and burr thickness with a micrometer. Ra values ranged between 1.89 and 3.86 µm, dimensional error values between 0.22 and 0.93%, and burr thickness between 2 and 34 µm. Regression analysis was performed, and linear models were obtained for each response. Results showed that roughness depends mainly on frequency, on the interaction of frequency and pulse width and on pulse width. The dimensional error depends on pulse width, frequency, and the interaction between pulse width and speed. Burr thickness is influenced by frequency, pulse width, and the interaction between frequency and speed. Multi-objective optimization showed that, in order to simultaneously minimize the three responses, it is recommended to use high frequency (80 Hz), high pulse width (0.6 ms), and high speed (140 mm/min). The present study will help to select appropriate laser cutting conditions in thin plates, in order to favor good surface finish and dimensional accuracy, as well as low burr thickness.

scholarly journals Experimental investigation of the electrochemical micromachining process of Ti-6Al-4V titanium alloy under the influence of magnetic field

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
T. Praveena Gopinath ◽  
J. Prasanna ◽  
C. Chandrasekhara Sastry ◽  
Sandeep Patil
Keyword(s):  
Magnetic Field ◽  
Titanium Alloy ◽  
Removal Rate ◽  
Electrochemical Machining ◽  
Machining Process ◽  
Electrochemical Micromachining ◽  
Machining Accuracy ◽  
Micro Hole ◽  
Neodymium Magnets ◽  
Pulse On Time

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.

A New Strategy of Cavity Cutting Trajectory Generation in High Speed Machining

2015 ◽  
Author(s):  
Yue Yin ◽  
LianShui Guo ◽  
Ning Han ◽  
Ji Zheng ◽  
Pengpeng Zhang
Keyword(s):  
Tool Life ◽  
High Speed ◽  
Machining Process ◽  
Free Form ◽  
Machining Accuracy ◽  
Programming System ◽  
Machining Efficiency ◽  
High Speed Machining ◽  
New Strategy ◽  
The Impact

High speed machining is widely used in manufacturing. For its high cutting speed, high feeding rate, and high machining accuracy, its requirements for cutting trajectory in high speed machining are so strict that only continuous and smooth trajectories with even cutting loads can lead to high machining efficiency and accuracy. The traditional row or ring machining trajectory fails to meet these requirements. In order to acquire the continuous and smooth machining trajectories, and to avoid load mutation in the machining process, some researchers developed a curvilinear cutting trajectory generating method based on partial differential equation. This trajectory, however, is still made up from free form curve segment, and unable to completely eliminate the effects on smoothness by line segment interpolation, which has a very adverse effect on the efficiency, tool life and machining accuracy. A new strategy to generate a continuous and smooth cavity cutting trajectories in high speed machining is introduced in this article. The new trajectory determines the necessity-nodes from outside (the boundary) to inside in the way of spiral cutting. It starts from the cavity center with spiral expanding, and each cutting loop adopts end connection between straight line and the tangent arc, meeting continuous first-order constraint satisfaction. The smooth trajectory reduces the amplitude and directing mutation of cutting force, thus effectively avoids the impact on the machining efficiency and machining accuracy by speeding down in the corner. The strategy also, by controlling the row space, ensures that there is no cutting residual. A cavity machining programming system based on this strategy is developed on Siemens UG-CAM module. The manufacturing of triangle cavities is studied as a case. It turns out that the new trajectory improves efficiency by 26.23% compared with the traditional one. It ensures a stable operation of the cutting tool in machining, therefore effectively extends the tool life. The main advantages are that the new strategy adopts the geometrical drawing strategy and the trajectories are all made up from the straight lines and the tangent arcs. The trajectory can greatly reduce NC code. It thoroughly removes the effort to mind the smooth, continuity and even cutting load of the tool-path.

Modelling and stress analysis for double-row curvic couplings

2020 ◽  
pp. 095440622097405
Author(s):  
Dayi Zhang ◽  
Cheng Yang ◽  
Tian He ◽  
Jixing Liu ◽  
Jie Hong
Keyword(s):  
Contact Stress ◽  
High Speed ◽  
Equivalent Stress ◽  
Machining Process ◽  
Double Row ◽  
Rotating Speed ◽  
Modified Method ◽  
Element Simulation ◽  
Bolt Preload ◽  
High Speed Rotation

This paper proposes a parameterized modelling method that considers the details of the machining process for double-row curvic couplings and presents a modified stress analytical method that can take the deep beam bending effect into account. The modified method provides a more accurate equivalent stress estimation than the classic Gleason method, which is demonstrated by the nonlinear finite element simulation. The contact stress and the contact status of the curvic couplings in high-speed rotation situations are analysed with the nonlinear FEA method under different loads. The results show that the strength of the weak regions of the double-row curvic couplings occur at the tooth root and the tooth to near the bolts. The bolt preload has the greatest influence on the contact stress and the contact status. The rotating speed reduces the bolt preload, causing the stress to decrease. The torque results in contact stress and contact status of different sides of the tooth being obviously different. Finally, the modified analytic method is recommended during the preliminary design, and the FEA method considering the contact effects is recommended for the detailing design.

Experimental Investigation on Electrochemical Micro Machining of Complex Shape Parts

2009 ◽  
Vol 419-420 ◽  
pp. 425-428 ◽  
Author(s):  
Yong Liu ◽  
Di Zhu ◽  
Yong Bin Zeng ◽  
Shao Fu Huang ◽  
Hong Bing Yu
Keyword(s):  
Process Parameters ◽  
Complex Shape ◽  
Electrochemical Process ◽  
Electrochemical Micromachining ◽  
Free Form ◽  
Machining Accuracy ◽  
Micro Machining ◽  
Peak Shape ◽  
Nurbs Curve ◽  
Pulse On Time

This paper introduces a method of machining free-form basis-NURBS curve into the field of micromachining. For achieving the optimization of the EMM (Electrochemical MicroMachining) process parameters, sets of experiments have been carried out to investigate the influence of some of the predominant electrochemical process parameters such as machining voltage, pulse on time, feed rate, and electrode peak shape on machining accuracy and quality. A complex shape with structures of several micrometers has been successfully obtained.

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