scholarly journals Electrochemical Drilling of Deep Small Holes in Titanium Alloys with Pulsating Electrolyte Flow

2014 ◽  
Vol 6 ◽  
pp. 167070 ◽  
Author(s):  
Yongbin Zeng ◽  
Xiaolong Fang ◽  
Yudong Zhang ◽  
Ningsong Qu
Keyword(s):  
Titanium Alloys ◽  
Removal Rate ◽  
Machining Accuracy ◽  
Pulsation Frequency ◽  
Average Pressure ◽  
Electrolyte Flow ◽  
Product Removal ◽  
Electrochemical Drilling ◽  
By Products ◽  
Small Holes

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.

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.

Research on Electrochemical Machining of Deep Small Holes with Positive and Negative Pulse Power

2021 ◽  
Vol 14 ◽  
Author(s):  
Zhaolong Li ◽  
Bingren Cao
Keyword(s):  
Power Supply ◽  
Pulse Width ◽  
Removal Rate ◽  
Electrochemical Machining ◽  
Machining Accuracy ◽  
Negative Pulse ◽  
Mass Removal ◽  
Nickel Based Alloy ◽  
Accuracy And Stability ◽  
Small Holes

Background: High-temperature alloy such as nickel-based alloy has become the main material for core components such as aero engines due to their high strength and good toughness. Therefore, it is of great significance to study how to improve the machining accuracy and stability of electrochemical machining (ECM) of deep small holes on the nickel-based alloy. The instantaneous high-density current during the pulse width of pulse ECM is beneficial to the dissolution of metal workpieces. Many experts and scholars have studied the pulse ECM of deep small holes. Objective: The purpose of this article is to propose and design a Positive And Negative Pulse (PANP) power supply to study the accuracy and stability of ECM of deep small holes on nickel-based alloys. Methods: First of all, an H-bridge composed of four MOSFET switches is designed to achieve PANP output in the main circuit of the power supply. Then, this paper studies the influence of the ratio of positive and negative pulses on short circuits, the influence of the ratio of positive and negative pulses on the mass removal rate, and the influence of the electrolyte concentration and pulse width on the mass removal rate. Finally, according to the obtained optimal parameters, the influence of electrolyte pressure on the average radial overcut of hole depth is analyzed. Results: The experimental results showed that the short-circuit frequency is reduced by more than 50% compared with non-negative pulse power supply; the ratio of positive and negative pulses, pulse width and electrolyte concentration and pressure were optimized by experiments to improve the mass removal rate of the workpiece and the average radial overcut of hole depth. Conclusion: The designed PANP power supply can improve the machining accuracy and stability of ECM of deep small holes on nickel-based alloys.

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.

Swirling Fluidized Bed Polishing: A New Non-Conventional Method of Surface Modification

2015 ◽  
Vol 813-814 ◽  
pp. 634-640
Author(s):  
N.K. Francis ◽  
K.G. Viswanadhan ◽  
M.M. Paulose
Keyword(s):  
Surface Modification ◽  
Fluidized Bed ◽  
Metal Removal ◽  
Complex Geometry ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Surface Finishing ◽  
Polished Surface ◽  
Work Piece ◽  
Machining Accuracy

Swirling Fluidized Bed Polishing (SFBP) is a non–traditional alternative abrasive flow surface finishing form of Fluidized Bed Machining (FBM) in which the former has special features to overcome certain significant limitations of the latter, namely the variation of the surface roughness vertically along the component surface and the screening effect owing to the complex contours in the work piece geometry. Owing to its ability to perform machining and generate polished surface from a roughness value of Ra 1.2μ to 0.2 μ within 8 hours of processing, this new method offers greater scope in the surface modification of rough machined surfaces with complex geometry such as component with ducts and grooves. This research focus on investigating the effect of abrasive particle concentration on metal removal rate per unit area of the specimen surface. 3D surface morphology analysis investigates the quality of the polished surface and the study of circumferential uniformity and machining accuracy analysis on a complex-contoured component further investigate its scope and relevance in industrial applications.

Effects of Cutting Parameters on the Surface Roughness of Ti6Al4V Titanium Alloys in Side Milling

2011 ◽  
Vol 175 ◽  
pp. 289-293 ◽  
Author(s):  
Hao Liu ◽  
Chong Hu Wu ◽  
Rong De Chen
Keyword(s):  
Surface Roughness ◽  
Titanium Alloys ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Cutting Parameters ◽  
Cutting Depth ◽  
Side Milling ◽  
Milling Parameters ◽  
Fine Grain

Side milling Ti6Al4V titanium alloys with fine grain carbide cutters is carried out. The influences of milling parameters on surface roughness are investigated and also discussed with average cutting thickness, material removal rate and vibration. The results reveal that the surface roughness increases with the increase of average cutting thickness and is primarily governed by the radial cutting depth.

Grinding-aided electrochemical discharge drilling in the light of electrochemistry

2018 ◽  
Vol 233 (6) ◽  
pp. 1896-1909 ◽  
Author(s):  
VG Ladeesh ◽  
R Manu
Keyword(s):  
Material Removal Rate ◽  
Borosilicate Glass ◽  
Chemical Etching ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Accuracy ◽  
Hybrid Technique ◽  
Machined Surface ◽  
Influence Of Process Parameters ◽  
Electrochemical Discharge

The electrically non-conductive materials like glass, ceramics, quartz, etc. are of great interest for many applications in modern industries. Machining them with high quality and at a faster rate is a challenging task. In this study, a novel technique called grinding aided electrochemical discharge drilling (G-ECDD) is demonstrated which uses a hollow diamond core drill as the tool for performing electrochemical discharge machining of borosilicate glass. The new hybrid technique enhances the material removal rate and machining accuracy to several folds by combining the thermal melting action of discharges and grinding action of the abrasive tool. This paper presents the experimental investigation on the material removal rate during G-ECDD of glass while using different electrolytes. An attempt has been made to explore the influence of electrolyte temperature on G-ECDD performance by maintaining the electrolyte at different temperatures. Experiments were conducted using three different electrolytes which include NaOH, KOH, and the mixture of both. The results obtained from this study revealed that an increase in temperature will favor chemical etching as well as electrochemical reaction rate. Also, it was observed that heating the electrolyte leads to an increase in the bubble density and enhances the ion mobility. This causes the formation of gas film at a faster rate and thereby improving the discharge activity. Thus, machining will be done at a faster rate. Better results are obtained while using a mixture of NaOH and KOH. From the microscopic images of the machined surface, it was observed that material removal mechanism in G-ECDD is a combination of grinding action, electrochemical discharges, and chemical etching. Response surface methodology was adopted for studying the influence of process parameters on the performance of G-ECDD. The new technique of grinding aided electrochemical discharge drilling proved its potential to machine borosilicate glass and simultaneously offers good material removal rate, repeatability, and accuracy.

scholarly journals An overview of conventional and non-conventional techniques for machining of titanium alloys

2020 ◽  
Vol 7 ◽  
pp. 34 ◽  
Author(s):  
Samuel Ranti Oke ◽  
Gabriel Seun Ogunwande ◽  
Moshood Onifade ◽  
Emmanuel Aikulola ◽  
Esther Dolapo Adewale ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Wear Rate ◽  
Tool Wear ◽  
Titanium Alloys ◽  
Metal Removal ◽  
Removal Rate ◽  
High Volume ◽  
Future Research ◽  
Tool Wear Rate ◽  
The Common

Machining is one of the major contributors to the high cost of titanium-based components. This is as a result of severe tool wear and high volume of waste generated from the workpiece. Research efforts seeking to reduce the cost of titanium alloys have explored the possibility of either eliminating machining as a processing step or optimising parameters for machining titanium alloys. Since the former is still at the infant stage, this article provides a review on the common machining techniques that were used for processing titanium-based components. These techniques are classified into two major categories based on the type of contact between the titanium workpiece and the tool. The two categories were dubbed conventional and non-conventional machining techniques. Most of the parameters that are associated with these techniques and their corresponding machinability indicators were presented. The common machinability indicators that are covered in this review include surface roughness, cutting forces, tool wear rate, chip formation and material removal rate. However, surface roughness, tool wear rate and metal removal rate were emphasised. The critical or optimum combination of parameters for achieving improved machinability was also highlighted. Some recommendations on future research directions are made.

Comparison between EBM and DMLS Ti6Al4V Machinability Characteristics under Dry Micro-Milling Conditions

2016 ◽  
Vol 836-837 ◽  
pp. 177-184 ◽  
Author(s):  
Zdenka Rysava ◽  
Stefania Bruschi
Keyword(s):  
Titanium Alloys ◽  
Surface Defects ◽  
Removal Rate ◽  
Cutting Speed ◽  
Micro Milling ◽  
Burr Formation ◽  
Tool Geometry ◽  
Work Piece ◽  
Dry Cutting ◽  
High Flexibility

This paper is aimed at evaluating the micro-machinability of the Ti-6Al-4V titanium alloy made by the means of two different Additive Manufacturing (AM) technologies. AM comprises promising technologies, widely used especially to produce parts made of difficult-to-cut materials, such as the titanium alloys. Titanium alloys represent one of the most widely used materials in the biomedical field, thanks to the high biocompatibility and excellent mechanical characteristics. Even if near-net-shape parts can be produced through AM, semi-finishing and/or finishing machining operations may be necessary to obtain the required surface finish and geometrical tolerances. Micro-milling technique is a soliciting solution for this kind of application due to its high flexibility, elevated material removal rate and direct contact between the tool geometry and work piece. Nevertheless, there are deficiencies in the literature regarding the study of micro-machinability of materials produced by means of AM technologies. In this paper, the micro-machinability of the Ti-6Al-4V alloy obtained by two different AM technologies, namely Electron Beam Melting (EBM) and Direct Metal Laser Sintering (DMLS), was studied and compared in order to assess the influence of the material as-delivered condition. Micro-milling tests were conducted on a high-precision 5-axis Kugler™ micro-milling centre under dry cutting conditions, by using uncoated, two fluted, flat-end-square, tungsten carbide tools with a diameter of 300 microns. The full immersion slotting strategy was chosen under full factorial design of experiments with two factors (cutting speed and feed per tooth). The micro-machinability was evaluated in terms of burr formation, surface integrity (surface topography and surface defects), tool damage and microstructure alterations.

Experimental Research on Ultrasonic Assisted Pulse Electrochemical Compound Finishing for Hard and Brittle Metal

2010 ◽  
Vol 42 ◽  
pp. 170-174
Author(s):  
Cheng Guang Zhang ◽  
Xue Ling Yang ◽  
Bo Zhao
Keyword(s):  
Particle Size ◽  
Surface Quality ◽  
Experimental Research ◽  
Material Removal Rate ◽  
Vibration Amplitude ◽  
Material Removal ◽  
Removal Rate ◽  
Machining Accuracy ◽  
Ultrasonic Assisted ◽  
Metal Materials

The experiment of ultrasonic assisted pulse electrochemical compound finishing is carried in this paper. The machining principle of the compound finishing is discussed in this paper. Processing experiments of compound finishing are carried out to study the effects of the main processing para- meters, including the particle size, the ultrasonic vibration amplitude, the minimum gap between the tool head and workpiece and the pulse voltage, on the material removal rate and the surface quality for hard and brittle metal materials. The curves of the corresponding relationships are also obtained. The study indicates that the processing velocity, machining accuracy and surface quality can be improved under the compound finishing, obtaining the processing technology conductions of the compound finishing. Introductions

Surface Effects and Residual Stresses in Electrolytically Ground Steel

1962 ◽  
Vol 84 (4) ◽  
pp. 483-489 ◽  
Author(s):  
J. Frisch ◽  
R. R. Cole
Keyword(s):  
Residual Stress ◽  
Corrosion Resistance ◽  
Residual Stresses ◽  
Material Removal ◽  
Removal Rate ◽  
Stress Distributions ◽  
Electrolyte Flow ◽  
Surface Conditions ◽  
Mechanical Removal ◽  
Grinding Conditions

The effects of electrolytic grinding on surface conditions and residual stress characteristics has been experimentally investigated. Surface finish, uniformity of material removal, and corrosion resistance are found to be dependent on mechanical removal rate as determined by wheel downfeed as well as electrolyte flow rate. Downfeeds of approximately 0.002 in. in the process do not produce measurable residual stresses and therefore it was further established that electrolytic grinding with moderate downfeeds can be used in place of swab etching techniques for evaluation of residual stress distributions. The maximum residual surface stresses were found to be not more than 22,000 psi, well below the yield strength of the material and were induced during the most severe grinding conditions.

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