Electrochemical drilling of multiple small holes with optimized electrolyte dividing manifolds

2017 ◽  
Vol 247 ◽  
pp. 40-47 ◽  
Author(s):  
Fang Xiaolong ◽  
Wang Xindi ◽  
Wang Wei ◽  
Qu Ningsong ◽  
Li Hansong
2014 ◽  
Vol 22 (3) ◽  
pp. 608-615 ◽  
Author(s):  
刘勇 LIU Yong ◽  
曾永彬 ZENG Yong-bin

2014 ◽  
Vol 6 ◽  
pp. 167070 ◽  
Author(s):  
Yongbin Zeng ◽  
Xiaolong Fang ◽  
Yudong Zhang ◽  
Ningsong Qu

Inherent characteristics of electrochemical drilling (ECD) mean that it is a major solution to the machining of deep small holes in difficult-to-cut materials. The removal of insoluble by-products from the machining gap determines the accuracy of control and limits process capacity. Pulsating electrolyte flow is introduced to enhance the removal rate of insoluble products by reducing the hold-down pressure caused by the electrolyte. Experiments are conducted to optimize a stimulus signal for the pulsation and to investigate the electrolyte pulsation frequency, pulsation amplitude, applied voltage, and electrode feed rate in the machining of deep small holes. The results indicate that optimized pulsating flow is effective in accelerating by-product removal and enhancing machining accuracy and maximum machining depth. With the optimized parameters of 5 Hz in frequency, 0.2 MPa in amplitude, and 0.5 MPa in average pressure, a deep hole was machined in titanium alloys of 20 mm depth and 1.97 mm averaged diameter.


1981 ◽  
Vol 46 (11) ◽  
pp. 2788-2794 ◽  
Author(s):  
Petr Novák ◽  
Ivo Roušar ◽  
Václav Cezner ◽  
Vladimír Mejta

The current density used in electrochemical machining can be increased only up to a certain value, above which the formation of electric sparks on the cathode (tool) is observed, whereby the latter and its insulation are damaged. The present work is devoted to the measurement of this critical current density for the case of electrochemical drilling of small holes by means of metal capillaries provided with an external insulation. The results are correlated by a criterion equation which gives the values of the limiting currents for sparking, IS , with an average error of ±9%.


Author(s):  
L. Andrew Staehelin

Freeze-etched membranes usually appear as relatively smooth surfaces covered with numerous small particles and a few small holes (Fig. 1). In 1966 Branton (1“) suggested that these surfaces represent split inner mem¬brane faces and not true external membrane surfaces. His theory has now gained wide acceptance partly due to new information obtained from double replicas of freeze-cleaved specimens (2,3) and from freeze-etch experi¬ments with surface labeled membranes (4). While theses studies have fur¬ther substantiated the basic idea of membrane splitting and have shown clearly which membrane faces are complementary to each other, they have left the question open, why the replicated membrane faces usually exhibit con¬siderably fewer holes than particles. According to Branton's theory the number of holes should on the average equal the number of particles. The absence of these holes can be explained in either of two ways: a) it is possible that no holes are formed during the cleaving process e.g. due to plastic deformation (5); b) holes may arise during the cleaving process but remain undetected because of inadequate replication and microscope techniques.


Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 828
Author(s):  
Zhaolong Li ◽  
Ye Dai

This paper presents a simulation and experimental study of the structure of small holes in GH4169 alloy electrolytic ally processed by tube electrodes with different characteristic power sources. It analyzes the multi-physical field coupling relationship of flow, temperature, and electric fields within the interstitial space. The results indicate that the tube electrode electrolytic processing of the GH4169 alloy small hole structure with a pulsed power supply has more uniform temperature and current density distribution within the gap, which is beneficial to the processing accuracy and smoothness of the small hole structure. Meanwhile, SEM was used to analyze the microscopic morphology of the electrode end surface during short-circuiting, and it was concluded that as the processing continued, the electrode end surface gradually produced a non-metallic oxide layer, which destroyed the electric field of the gap and affected the processing stability. The use of high-frequency positive and negative pulse power can effectively avoid the generation of a non-metallic oxide layer. Through the combination of simulation analysis and experimental verification, it is concluded that increasing electrolyte pressure in stages can effectively improve machining accuracy and stability. The interstitial current increases as the feed rate of the tool electrode increases, and the diameter of the machined small hole decreases as it increases.


2014 ◽  
Vol 53 (10) ◽  
pp. 2246
Author(s):  
Xiaomei Chen ◽  
Andrew Longstaff ◽  
Simon Fletcher ◽  
Alan Myers

Author(s):  
Alper Uysal ◽  
Mihrigül Altan

Engineering plastics have wide applications in different fields of industry due to their light weight and easy shaping. In manufacturing multi-component products, assembly is an inevitable stage and drilling is one of the necessary processes before joining of the components of these products. In this study, two of the most common types of engineering plastics, polyacetal (POM) and cast polyamide (castamide), were drilled with twist drills of 0.5 mm and 1 mm diameters, under different cutting speeds and feeds. In determining the accuracy of the drilled small holes, a mathematical approach was used in which least square circle method was applied and radial error of the each drilled hole was obtained. Thus, the hole accuracy could be determined without measuring equipment such as coordinate measurement machine. It has been seen that POM gave better hole accuracy than cast polyamide due its thermal and tribological properties. The effects of feed and cutting speed on the radial error were also investigated. POM did not show apparent difference in radial error according to the cutting parameters while cast polyamide showed lower radial error in higher feeds with 0.5 mm of drill tool and lower radial error with 1 mm of drill tool. Additionally, the radial error could be reduced with decrease of spindle speed at higher feed.


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