scholarly journals Analysis of Multi-Physics Coupling of Small Holes in GH4169 Alloy by Electrolytic Processing of Tube Electrodes

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 828
Author(s):  
Zhaolong Li ◽  
Ye Dai
Keyword(s):  
Oxide Layer ◽  
Small Hole ◽  
Machining Accuracy ◽  
Tool Electrode ◽  
Metallic Oxide ◽  
Power Sources ◽  
Processing Stability ◽  
Hole Structure ◽  
Gh4169 Alloy ◽  
Small Holes

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.

Chip-Ejection Mechanism and Experimental Study of Water Dispersant Dielectric Fluid on Small-Hole EDM

2010 ◽  
Vol 97-101 ◽  
pp. 4111-4115 ◽  
Author(s):  
Ming Rang Cao ◽  
Sheng Qiang Yang ◽  
Wen Hui Li ◽  
Shi Chun Yang
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Tap Water ◽  
Dielectric Liquid ◽  
Small Hole ◽  
Dielectric Fluid ◽  
Tool Electrode ◽  
Machining Quality ◽  
Hole Machining

The small hole EDM is one main method of micro holes machining and applied very widely. But it’s machining efficiency is low and machining stability is bad, which is more obvious because of chip-ejection difficulty when the ratio of length to diameter is rather large. Secondary discharge caused by chip-ejection difficulty not only makes the material removal rate reduce, but also causes geometric tolerance and affects product performance. Based on dispersion mechanism study of the water dispersant, the influence of the water dispersant is analyzed to chip-ejection, material removal rate and machining quality of the high-speed small-hole EDM. By contrasting the machining effect on using tap water with disperser dielectric liquid during electric spark small hole machining, adding the certain proportion disperser in water-based dielectric liquid may increase the material removal rate, decrease the tool wear rate, improve the effective impulse numbers, obviously reduce the second discharge number, and the taper of tool electrode and hole becomes small, so the hole machining quality enhances.

Research on Side-Insulation of Tool Electrode for Micro Electrochemical Machining

2009 ◽  
Vol 60-61 ◽  
pp. 380-387 ◽  
Author(s):  
Gai Hong Liu ◽  
Yong Li ◽  
Xu Peng Chen ◽  
Shan Jin Lv
Keyword(s):  
Spin Coating ◽  
Electrochemical Machining ◽  
Processing Parameters ◽  
Machining Accuracy ◽  
Tool Electrode ◽  
Insulation Material ◽  
Durability Test ◽  
Micro Ecm ◽  
Micro Tool ◽  
Micro Array

In micro electrochemical machining (micro ECM), side-insulation of tool electrode can significantly improve the machining accuracy, especially for high aspect ratio structures. This paper presented a new side-insulation approach for not only micro single electrodes but also micro array electrodes, in which spin-coating and room curing are used to coat the micro tool electrodes with a very thin film of polymer, followed by an end-rubbing process to remove the insulation material from the electrode end surfaces. Processing parameters of spin-coating were optimized experimentally, and side-insulated micro single electrodes with a double-layer epoxy coating of 3m thickness were prepared. Experiments were made to test the performance of the side-insulation film under simulated micro ECM conditions. And the results demonstrated good insulativity and high adherence strength in a 6-hour durability test. Also side-insulation for micro array electrodes was performed using this approach.

scholarly journals Increasing number of small hole diameter microfracture compared with traditional microfracture in same size cartilage defects and effect of HA based aselluler scaffold. An animal study

2017 ◽  
Vol 5 (2_suppl2) ◽  
pp. 2325967117S0008
Author(s):  
Gökçer Uzer ◽  
Nuh Mehmet Elmadağ ◽  
Fatih Yıldız ◽  
Yunus Güzel ◽  
Olgu Enis Tok
Keyword(s):  
Small Diameter ◽  
Small Hole ◽  
Cartilage Tissue ◽  
Cartilage Defects ◽  
Constant Thickness ◽  
Control Group ◽  
Trochlear Groove ◽  
Acellular Matrix ◽  
Diameter Hole ◽  
Small Holes

Purpose: The purpose of this study is small hole microfracure method comparing with traditional microfracture method and investigation of effect of HA based acellular matrix scaffold on microfracture area. Materials-Methods: 21 Twenty-one New Zealand white rabbits were used for the in vitro portion of this study, bilateral knee joint from the same rabbit were same technic. An articular cartilage defect was established in the femoral trochlear groove about 5 mm. Control group was established alone microfracture (MF). 6 groups were formed in this study and each group has 3 rabbits and their six knees. In 3 groups were applied different number of small diameter hole microfracture (4,5,6 small holes microfracture respectively)and the other 3 groups were applied different number of small diameter hole microfracture (4,5,6 small holes micro fracture respectively added HA based acellular matrix scaffold in the same size ostechondral lesion. The regenerated tissues were harvested for gross morphology, histology at 12 weeks postoperatively. Results: Cartilage were regenerated, maintaining a constant thickness of cartilage. MF group has worse Wakitani scores than 6 small diameter holes mıcrofracture groups(group 6 and group 7) in either parameter of the score. (p=0,043, p=0,016) Matrix addition did not contribute to healing. (p=1,000) Conclusions: Increasing number of the small diameter holes microfracture (minimum %15 of defect size) improves cartilage repair compared with traditional MF in the same size ostechondral lesion. Also small diameter holes microfracture combined with HA-based AM implantation didn’t result in improved quality of the regenerated cartilage tissue.

Study of Pulse Electrochemical Machining Performance of Deep-Small Hole on Nickel-Based Alloy

2011 ◽  
Vol 204-210 ◽  
pp. 1830-1834
Author(s):  
Zhao Long Li ◽  
Shi Chun Di
Keyword(s):  
Base Alloy ◽  
Removal Rate ◽  
Electrochemical Machining ◽  
Machining Process ◽  
Machining Accuracy ◽  
Machining Performance ◽  
Math Model ◽  
Technical Parameters ◽  
Pulse Electrochemical Machining ◽  
Small Holes

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.

scholarly journals Small Hole Filling in ITK

2011 ◽  
Author(s):  
David Doria
Keyword(s):  
Simple Technique ◽  
Small Hole ◽  
Hole Filling ◽  
Small Holes

This code provides an implementation of a simple technique to fill small holes in an image. We use a multi-pass method that fills pixels on the border of a hole with the average of its non-hole 8-connected neighbors. This process is repeated until all holes are filled.The code is available here: https://github.com/daviddoria/SmallHoleFiller

scholarly journals Limiting current density in electrochemical micromachining

2018 ◽  
Author(s):  
Chuanjun Zhao ◽  
Lizhong Xu
Keyword(s):  
Current Density ◽  
Steel Plate ◽  
Limiting Current ◽  
Diffusion Current ◽  
Electrochemical Micromachining ◽  
Machining Accuracy ◽  
Tool Electrode ◽  
Limiting Current Density ◽  
Machining Speed ◽  
Small Clearance

<p class="PaperAbstract"><span lang="EN-US">In this paper, a method of calculating the diffusion current density on the electric pole in the electrochemical micromachining is proposed. Changes of the diffusion current with system factors are investigated from which a method of increasing the diffusion current density on the electric pole under small clearance between the hole and the tool is proposed. This is the electrochemical micromachining method using vibrating tool electrode. Using this method, an etching experiment on a steel plate is performed which shows that a reasonable machining speed and high machining accuracy are simultaneously obtained.</span></p>

scholarly journals Influence of Different Tool Electrode Materials on Electrochemical Discharge Machining Performances

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1077
Author(s):  
Islam Md. Rashedul ◽  
Yan Zhang ◽  
Kebing Zhou ◽  
Guoqian Wang ◽  
Tianpeng Xi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electrode Materials ◽  
Removal Rate ◽  
Machining Accuracy ◽  
Tool Electrode ◽  
Electrode Wear ◽  
Electrochemical Discharge Machining ◽  
Electrochemical Discharge ◽  
Micro Channels

Electrochemical discharge machining (ECDM) is an emerging method for developing micro-channels in conductive or non-conductive materials. In order to machine the materials, it uses a combination of chemical and thermal energy. The tool electrode’s arrangement is crucial for channeling these energies from the tool electrode to the work material. As a consequence, tool electrode optimization and analysis are crucial for efficiently utilizing energies during ECDM and ensuring machining accuracy. The main motive of this study is to experimentally investigate the influence of different electrode materials, namely titanium alloy (TC4), stainless steel (SS304), brass, and copper–tungsten (CuW) alloys (W70Cu30, W80Cu20, W90Cu10), on electrodes’ electrical properties, and to select an appropriate electrode in the ECDM process. The material removal rate (MRR), electrode wear ratio (EWR), overcut (OC), and surface defects are the measurements considered. The electrical conductivity and thermal conductivity of electrodes have been identified as analytical issues for optimal machining efficiency. Moreover, electrical conductivity has been shown to influence the MRR, whereas thermal conductivity has a greater impact on the EWR, as characterized by TC4, SS304, brass, and W80Cu20 electrodes. After that, comparison experiments with three CuW electrodes (W70Cu30, W80Cu20, and W90Cu10) are carried out, with the W70Cu30 electrode appearing to be the best in terms of the ECDM process. After reviewing the research outcomes, it was determined that the W70Cu30 electrode fits best in the ECDM process, with a 70 μg/s MRR, 8.1% EWR, and 0.05 mm OC. Therefore, the W70Cu30 electrode is discovered to have the best operational efficiency and productivity with performance measures in ECDM out of the six electrodes.

A Study on the Method for Punching Small Holes with Cold Stamping Dies

2013 ◽  
Vol 456 ◽  
pp. 358-362
Author(s):  
Jian Hua Ning ◽  
Zheng Ping Hai
Keyword(s):  
Small Hole ◽  
Stamping Dies ◽  
Deformation Modes ◽  
Cold Stamping ◽  
Small Holes

this paper first determines the deformation modes of punching small-hole punches by analyzing the forms of the stress applied to die working parts. It analyzes the disadvantages of existing methods for preventing the buckling problem in punching small holes such as protective jackets and proposes a method for preventing the buckling of punches by reducing the punching force so as to make it possible to punch smaller holes.

Electrochemical Machining of Micro-Structures With Nanosecond Pulses

2007 ◽  
Author(s):  
Zhaoyang Zhang ◽  
Di Zhu ◽  
Ningsong Qu ◽  
Kun Wang
Keyword(s):  
Pulse Duration ◽  
Electrochemical Machining ◽  
Experimental System ◽  
Machining Accuracy ◽  
Tool Electrode ◽  
Voltage Amplitude ◽  
Nanosecond Pulses ◽  
Micro Ecm ◽  
Micro Tool ◽  
Micro Structures

Electrochemical machining (ECM) is considered an advanced and promising technique due to several special advantages, such as non-contact machining without cutting force, no tool wear and heat-affected layer, etc. Base on the experimental results of micro-ECM, the influence of predominant process parameters, i.e. electrolyte concentration, pulse duration, period and voltage amplitude of power supply, on machining accuracy were investigated and discussed. Experimental showed that lower voltage amplitude and shorter pulse duration in micro-ECM process could produce more accurate micro structure shape. Using the self-developed experimental system, the micro tool-electrode and the complex micro-structures were sequentially machined. Upon the application of ultrashort voltage pulses, the letters with 20μm in line width were fabricated stably by the W tool electrode with 10μm diameter.

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