scholarly journals Process Control in Jet Electrochemical Machining of Stainless Steel through Inline Metrology of Current Density

Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 261 ◽  
Author(s):  
Matin Yahyavi Zanjani ◽  
Matthias Hackert-Oschätzchen ◽  
André Martin ◽  
Gunnar Meichsner ◽  
Jan Edelmann ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Process Control ◽  
Current Density ◽  
Electrochemical Machining ◽  
High Strength ◽  
Special Focus ◽  
Machining Processes ◽  
Product Features ◽  
Mechanical Machining ◽  
Jet Electrochemical Machining

Jet electrochemical machining (Jet-ECM) is a flexible method for machining complex microstructures in high-strength and hard-to-machine materials. Contrary to mechanical machining, in Jet-ECM there is no mechanical contact between tool and workpiece. This enables Jet-ECM, like other electrochemical machining processes, to realize surface layers free of mechanical residual stresses, cracks, and thermal distortions. Besides, it causes no burrs and offers long tool life. This paper presents selected features of Jet-ECM, with special focus on the analysis of the current density during the machining of single grooves in stainless steel EN 1.4301. Especially, the development of the current density resulting from machining grooves intersecting previous machining steps was monitored in order to derive systematic influences. The resulting removal geometry is analyzed by measuring the depth and the roughness of the machined grooves. The correlation between the measured product features and the monitored current density is investigated. This correlation shows that grooves with the desired depth and surface roughness can be machined by controlling current density through the adjustment of process parameters. On the other hand, current density is sensitive to the changes of working gap. As a consequence of the changes of workpiece form and size for the grooves intersecting premachined grooves as well as the grooves with a lateral gap, working gap, and current density change. By analyzing monitoring data and removal geometry results, the suitability of current density inline monitoring to enable process control is shown, especially with regards to manufacture products that should comply with tight predefined specifications.

scholarly journals (ECS 234th) Multiphysics Modeling Prediction of Electrochemically Machined Through-Hole Geometries

2018 ◽  
Author(s):  
Brian Skinn ◽  
Tim Hall ◽  
Stephen Snyder ◽  
KP Rajurkar ◽  
Jennings E. Taylor
Keyword(s):  
Electrochemical Machining ◽  
High Strength ◽  
Mirror Image ◽  
Simulation Software ◽  
Manufacturing Technology ◽  
Tungsten Alloy ◽  
Machining Processes ◽  
Predictive Tool ◽  
Multiphysics Simulation ◽  
Through Hole

Electrochemical machining (ECM) is a manufacturing technology that allows metal to be precisely removed by electrochemical oxidation and dissolution into an electrolyte solution. ECM is suited for machining parts fabricated from “difficult to cut” materials and/or parts with complicated and intricate geometries. In ECM, the workpiece is the anode and the tool is the cathode in an electrochemical cell; by relative movement of the shaped tool into the workpiece, the mirror image of the tool is “copied” or machined into the workpiece. Compared to mechanical or thermal machining processes where metal is removed by cutting or electric discharge/laser machining, respectively, ECM does not suffer from tool wear or result in a thermally damaged surface layer on the workpiece. Consequently, ECM has strong utility as a manufacturing technology for fabrication of a wide variety of metallic parts and components, and includes machining, deburring, boring, radiusing and polishing processes. ECM provides particular value in that application is straightforward to high strength/tough and/or work-hardening materials such as high strength steel, chrome-copper alloy (C18200), nickel alloy (IN718), cobalt-chrome alloy (Stellite 25) and tantalum-tungsten alloy (Ta10W), since the material removal process involves no mechanical interaction between the tool and the part. A variety of production applications are envisioned as well suited for ECM techniques.One notable difficulty with ECM, common to a variety of manufacturing operations, is an inability to predict a priori the tool and process parameters required in order to satisfy the final specifications of the fabricated part. In this talk, Faraday will present results from ongoing development work of a physics-based design platform to predict optimal ECM tool shape using commercially available multiphysics simulation software. This predictive capability is anticipated to dramatically shorten the process/tooling development cycle, eliminating much or all of the iterative prototyping necessary in the absence of a predictive tool. The main focus of this talk will be a comparison of through-holes fabricated by CM in flat plate and/or tube geometries to those predicted by multiphysics simulation. The various physics included in the models to enable accurate simulations will be discussed, along with any (semi-)empirical simplifying assumptions made to accelerate execution of the simulations. The overarching objective of the current and future work, to demonstrate accurate modeling of ECM through-hole features of progressively increasing experimental complexity, will also be presented.

Characteristics of Electrochemical Machining Passive Films on Stainless Steel S304

2013 ◽  
Vol 705 ◽  
pp. 197-202 ◽  
Author(s):  
Ze Fei Wei ◽  
Xing Hua Zheng ◽  
Ning Ma
Keyword(s):  
Stainless Steel ◽  
Passive Film ◽  
Current Density ◽  
Electrolyte Concentration ◽  
Electrochemical Machining ◽  
Passive Films ◽  
Theoretical Formula ◽  
Film Morphology ◽  
Experimental Subjects ◽  
Change Tendency

Stainless steel S304 was used as experimental subjects, the influences of current density on the passive film morphology, thickness and removal quantity were studied by quantitative experiments. The effect of electrolyte concentration on polarization curve characteristics of stainless steel S304 was qualitatively analyzed. The results show that the passive film morphologies dandify with increasing current density; passive film thickness increases with increasing current density; the change tendency of removal with the current density is consistent with the theoretical formula.

Primary Research on Jet ECM Processing of Difficult to Cut Materials

2013 ◽  
Vol 554-557 ◽  
pp. 1793-1799 ◽  
Author(s):  
Piotr Lipiec ◽  
Dominik Wyszynski ◽  
Sebastian Skoczypiec
Keyword(s):  
Current Density ◽  
Large Scale ◽  
Electrochemical Machining ◽  
Current Density Distribution ◽  
Electrochemical Process ◽  
Experiment Planning ◽  
Work Piece ◽  
Machined Surface ◽  
Jet Electrochemical Machining ◽  
Electrolyte Jet

Unconventional production techniques became interesting and promising part of manufacturing methods. They provide complementary, to traditional loss methods, solutions enabling use of high - performance engineering materials for construction of machinery and industrial equipment. By using properly selected methods or their hybrids difficult to cut materials as steel, alloys, sintered materials and composites can be processed. Among the wide variety of unconventional methods of materials forming, particular attention should be given to electrochemical machining, which has been successfully used in various industries. This fact proves attractiveness and versatility of ECM. The method could be used on large scale and many variations was developed as each application requires an individual approach and has own requirements. One of the least known and described type of electrochemical machining is jet ECM where the electrolyte jet stream acts as a tool. In this kind of machining, the part is shaped only in the area where the electrolyte jet strikes the surface. This is due to the fact that the current density distribution is located just below the stream. In the area around the jet hitting the work piece thin electrolyte layer is formed. Thickness of that layer is growing rapidly. Since the electrolyte jet machining is an electrochemical process, the machined surface has all the benefits of ECM. There is no burrs and low temperature of the process prevents appearance of cracks and there is no heat-affected zone. Electrolyte jet machining can be used as well as in macro and micro drilling, turning, texturing, and electroplating. The process can be controlled by proper selection of such parameters as time, the current density and the diameter of the jet. Jet ECM can be used not only for material removal, but also for coloration (passivation) by means of anodic dissolution. 3D shaping of elements is also possible by controlling the current and the velocity of the electrolyte stream. In addition, by changing the polarity of the applied voltage it is possible to use this method in broadly considered electroplating. The paper presents results of the initial research on jet electrochemical machining (jet ECM) of acid proof steel and tungsten carbide. The material processing was carried in two ways – drilling holes and shaping grooves. Shaping was realized in milling and face turning regime. The influence of the two basic process parameters voltage and pressure was examined. In order to get rough information about the jet ECM process experiment planning method was applied. Obtained results enable planning of the further extended research.

scholarly journals Effect on Material Removal Rate and Surface Finish in ECM Process When Machining Stainless Steel-316 with Cu Electrode

2019 ◽  
Vol 8 (4) ◽  
pp. 2933-2941
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Process Parameters ◽  
Surface Finish ◽  
Feed Rate ◽  
Electrolyte Concentration ◽  
Removal Rate ◽  
Electrochemical Machining ◽  
Machining Process ◽  
Machining Processes

Electrochemical Machining process is one of the popular non-traditional machining processes which is used to machine materials such as super alloys, Ti-alloys, stainless steel etc. Its working principle is based upon Faraday law of electrolysis. The aim of the present work is to optimize the ECM process parameters with the combination of SS 316 (job material) and Copper electrode (tool material). To explore the effect of ECM process parameters such as electrolyte concentration, voltage and current, feed rate on MRR and surface finish (Ra) of the job, total 27 experiments were conducted as per experimental scheme. The results of these experiments revealed that increase in electrolyte concentration decrease the mrr and surface roughness initially increases then decreases. Further, increase in current increases mrr initially and then decreases, surface roughness also increases. It is also noticed that increase in Feed rate mrr decreases and then increases, also surface roughness decreases then increases. Through RSM analysis it is found that the optimum conditions for maximum MRR, and minimum Surface roughness (Ra) is electrolyte concentration 150gm/lit, Voltage 13.5 V & feed 0.8 mm/min. The findings are discussed in the light of previous researches and subsequently conclusions are drawn.

A TEM microscopical investigation of the magnetic domain structure of a metastable austenitic stainless steel

1994 ◽  
Vol 52 ◽  
pp. 696-697
Author(s):  
G. Fourlaris ◽  
T. Gladman
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cold Rolling ◽  
Solution Treatment ◽  
Magnetic Domain ◽  
High Strength ◽  
Medium Carbon Steel ◽  
Magnetic Characteristics ◽  
Metastable Austenitic Stainless Steel

Stainless steels have widespread applications due to their good corrosion resistance, but for certain types of large naval constructions, other requirements are imposed such as high strength and toughness , and modified magnetic characteristics.The magnetic characteristics of a 302 type metastable austenitic stainless steel has been assessed after various cold rolling treatments designed to increase strength by strain inducement of martensite. A grade 817M40 low alloy medium carbon steel was used as a reference material.The metastable austenitic stainless steel after solution treatment possesses a fully austenitic microstructure. However its tensile strength , in the solution treated condition , is low.Cold rolling results in the strain induced transformation to α’- martensite in austenitic matrix and enhances the tensile strength. However , α’-martensite is ferromagnetic , and its introduction to an otherwise fully paramagnetic matrix alters the magnetic response of the material. An example of the mixed martensitic-retained austenitic microstructure obtained after the cold rolling experiment is provided in the SEM micrograph of Figure 1.

Studying The Effect of a New Mixed Cutting Fluid on Surface Roughness

2020 ◽  
Vol 38 (11A) ◽  
pp. 1593-1601
Author(s):  
Mohammed H. Shaker ◽  
Salah K. Jawad ◽  
Maan A. Tawfiq
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Cutting Parameters ◽  
Machining Process ◽  
Cutting Fluid ◽  
Depth Of Cut ◽  
Cutting Fluids ◽  
Machining Processes ◽  
Dry Cutting ◽  
Cutting Speeds

This research studied the influence of cutting fluids and cutting parameters on the surface roughness for stainless steel worked by turning machine in dry and wet cutting cases. The work was done with different cutting speeds, and feed rates with a fixed depth of cutting. During the machining process, heat was generated and effects of higher surface roughness of work material. In this study, the effects of some cutting fluids, and dry cutting on surface roughness have been examined in turning of AISI316 stainless steel material. Sodium Lauryl Ether Sulfate (SLES) instead of other soluble oils has been used and compared to dry machining processes. Experiments have been performed at four cutting speeds (60, 95, 155, 240) m/min, feed rates (0.065, 0.08, 0.096, 0.114) mm/rev. and constant depth of cut (0.5) mm. The amount of decrease in Ra after the used suggested mixture arrived at (0.21µm), while Ra exceeded (1µm) in case of soluble oils This means the suggested mixture gave the best results of lubricating properties than other cases.

METGLAS MBF-30/30A

Alloy Digest ◽  
1981 ◽  
Vol 30 (12) ◽  
Keyword(s):  
Stainless Steel ◽  
Metallic Glass ◽  
Physical Properties ◽  
Flow Characteristics ◽  
High Strength ◽  
Thin Foil ◽  
Heat Treating

Abstract METGLAS MBF-30A is a brazing foil in ductile, flexible metallic-glass form (a similar grade, MBF-30, is identical except that it has larger dimensional tolerances). This foil provides an alloy with high strength at both elevated and room temperatures. It can be used to join highly stressed stainless steel and heat-resisting alloy components. The excellent flow characteristics of this alloy recommend it for assemblies with good fit-up and tight-tolerance joints. It works well on thin-foil, honeycomb designs and on fairly heavy components. This datasheet provides information on composition, physical properties, and microstructure. It also includes information on heat treating. Filing Code: Ni-273. Producer or source: Allied Corporation.

AISI No. 633

Alloy Digest ◽  
1981 ◽  
Vol 30 (7) ◽  
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Stainless Steels ◽  
High Strength ◽  
Heat Treating ◽  
Corrosion Resistant ◽  
Martensitic Stainless Steels ◽  
Steel Mills ◽  
Temperature Performance ◽  
Structural Applications

Abstract AISI No. 633 is a chromium-nickel-molybdenum stainless steel whose properties can be changed by heat treatment. It bridges the gap between the austenitic and martensitic stainless steels; that is, it has some of the properties of each. Its uses include high-strength structural applications, corrosion-resistant springs and knife blades. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-389. Producer or source: Stainless steel mills.

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