Electrochemical Machining Of Metals Research Articles

A Hydrodynamic Model of the “Jet” Phenomenon in Electrochemical Machining of Metals

A Hydrodynamic Model of the “Jet” Phenomenon in Electrochemical Machining of Metals

Cavitation flow of an ideal incompressible fluid in the electrochemical machining of metals

Abstract The limiting simplest model of the non-linear two-dimensional problem of the electrochemical machining of metals taking account of the attached cavitation is constructed on the basis of a model of an ideal electrochemical shaping process and the theory of ideal incompressible fluid jets. A solution is obtained related to the determination of the steady shape of the surface of the component (anode) taking account of the cavity formed in the machining on the cathode tool boundary. The results of the calculations show that the model reflects the qualitative effects related to the effect of the added cavity on the shape of the machined component.

Role of laser radiation in activating anodic dissolution under electrochemical machining of metals and alloys

The specific features of electrochemical dissolution of the 12X18H9T stainless steel, the OT-4 titanium alloy and the BK8 hard alloy in the sodium nitrate water solution exposed to 1.06 micrometer wavelength laser radiation were considered. It is found that depassivation of the anode surface is the main mechanism of laser activation in electrochemical dissolving of materials. It is established that the maximum efficiency of laser electrochemical machining is achieved at a pulse repetition frequency of 10 kHz laser radiation. It is connected with the photoactivation mechanism of electrolyte solution molecules, which increases their reaction capacity.

Evaluation of shaping accuracy upon electrochemical machining of metals

Electrochemical dimensional machining (ECDM) is based on the local high rate anodic dissolution of metals [1–5]. Upon ECDM of metals and alloys, the following results are achieved: the provision of high rates of anodic dissolution, the quality of the machined surface, and shaping accuracy both in terms of the shape and dimensions. High rates of anodic dis� solution of the majority of metals and alloys, as well as the quality of the formed surface, are implemented by way of the selection of the appropriate electrolyte solutions and modes of electrochemical machining [6]. At the same time, the achievement of satisfactory accuracy of electrochemical shaping is a far more complicated problem. The complicity of its solution is related to the fact that, for simultaneous provision of, for instance, productivity and accuracy, it is necessary to meet mutually exclusive conditions. For example, electrolytes with sufficient electric conductance and

Simulation of precision electrochemical machining of metals by a segmented cathode

Bulge formation in the process of electrochemical machining by a flat tool electrode with an insulated area is studied. Based on a step function of the current efficiency, precision machining is simulated. The solution of a nonstationary problem shows that a limiting mode with the current density equal to its critical value is established in a finite time.

One scheme of electrochemical machining of metals by a curvilinear electrode tool

The nonlinear plane problem of the evolution of the shape of the metal surface (anode) during electrochemical machining by a curvilinear cathode of symmetric shape is solved. A condition is obtained which allows one to determine the position of the point of transition from the zone of anodic metal dissolution to the region in which machining stops.

One problem of the theory of dimensional electrochemical machining of metals

A method is proposed for determining the shape of the anode-article boundary for a given shape of the cathode-tool in plane problems of the theory of dimensional electrochemical machining of metals. Under the assumptions used, the boundary of the anode-article is divided into the working zone, where metal dissolution occurs, and an adjacent zone, where the treatment (dissolution) is terminated. The initial problem is reduced to a problem of a fictitious plane-parallel potential flow of an ideal fluid with a nonlinear condition on the free surface. The point of separation of the fictitious flow from the solid boundary corresponds to the point separating these two zones of the anode boundary. The Brillouin-Will condition of smooth separation is imposed at the separation point to construct a closed system of equations determining the problem solution.

A hydrodynamic interpretation of a problem in the theory of the dimensional electrochemical machining of metals

A method of determining the form of the anode-blank boundary for a specified form of the cathode tool in plane problems of the theory of the dimensional electrochemical machining of metals is proposed. Within the assumptions made, the anode-blank boundary is divided into a working zone, in which solution of the metal occurs, and a region next to it in which the machining ceases. The initial problem is reduced to a problem of plane-parallel potential flow of an ideal liquid with non-linear conditions on its surface. The point which separates these two regions of the anode boundary corresponds to the point where the jet separates from the solid boundary. The Brillouin-Villat smooth separation condition is specified when compiling the closed system of equations at the point where the jet separates.

A scheme for the electrochemical machining of metals by a cathode tool with a curvilinear part of the boundary

The solution of a non-linear plane problem in the theory of the electrochemical machining of metals, associated with the determination of the shape of a surface (the anode) during its treatment with a cathode tool with a curvilinear part of the boundary, is obtained by methods developed for problems of jet flow past curvilinear obstacles. A condition is obtained which is identical to the well known Brillouin-Villat condition in fluid dynamics for smooth separation, the use of which enables one to determine the position of the transition point from the zone of steady treatment conditions into a region where the dissolution of the metal does not occur. The fixed shapes of the anode boundary are found for two cathode configurations.

Anode-Shape Determination with Allowance for Electrolyte Properties in Problems of Dimensional Electrochemical Machining of Metals

Based on the boundary-element technique, a method for determining the contour of an anode-workpiece with a prescribed shape of a cathode-tool is suggested for plane problems of dimensional electrochemical machining of metals. Within the scope of the assumptions made, the original problem is reduced to the problem of a fictitious flow of an ideal fluid with free surfaces. The allowance for the machining mode and electrolyte properties yields a nonlinear condition at the free surface.

鉄を電解加工した時の陽極溶解, 加工条件, 加工性について

Many industrial merits are found in electro-chemical machining of metals as compared with other conventional methods of metal working though the accuracy of the worked piece by electro- chemical machining is not very satisfactory.The author investigated anodic dissolution, working condition, and workability of removing iron in electro-chemical machining and the following experimental results were obtained:(1) Electro-chemical machining of iron could be successfully performed when halogen compounds were used for electrolyte.(2) The accuracy of worked piece was variant depending on distance between electrodes, nature of electrolyte and chemical composition and microstructure of working material.Electro-chemical machining of irons of almost same composition in sodium chloride solution gave variable results of anodic polarization potential depending upon the microstructure of working material.When anodic polarization potential was lower, both current efficiency and penetration rate were higher and also the removing was more effective.