Papers by Keyword: Electrode Design

Abstract: This work presents an experimental work in orbiting EDM which design of the electrode used adopt the non-uniform offset method formulated by the authors. A brief explanation about the design principle is presented in this paper as well as comparison of experimental machining results between uniform tool offset and the said method. The design method is implemented in a commercial CAD software and the system has been proven effective to cut design lead time and reduce error. The experimental part on orbiting EDM adopting the said-method yields improved machining accuracy and machined surface quality.

Abstract: A shrouded turbine blisk is taken as the research object. Based on NURBS surface modeling theory and by using SolidWorks software, a 3D model of the blisk was gotten. An electrode was designed according to the characteristic of channel between two blades of the blisk. A set of fixtures for manufacturing the blisk was designed, which can realize measurement on-line. Computer simulation of manufacturing the blisk was conducted. The simulation results show that there is no interference between the blisk and the electrode. So the feasibility of manufacture is verified. The simulation results have provided an effective basis for the subsequent processing of the blisk.

Abstract: In die-sinking EDM, the electrode is moved only in the Z-axis direction, while in oscillating EDM, electrodes are oscillated in both the X-axis and Y-axis directions to realize high accuracy machining. There are many ways of designing electrodes for oscillating EDM. However, because the form of electrodes and subsequently the oscillating patterns of these electrodes depend on the shapes of the die/mold used, they become complicated when the die/mold shape is complicated, and electrode design takes hours in such cases. This paper therefore proposes a new approach of designing electrodes for oscillating EDM. Some oscillating patterns based on the proposed approach are also analyzed from the viewpoint of usefulness.

Abstract: Anode for direct methanol fuel cell (DMFC) was fabricated on Nafion 117 membrane by electrophoretic deposition (EPD) method. An ethanol suspension containing Pt-Ru/C and Nafion ionomer was utilized, in which Pt-Ru/C and Nafion ionomer formed composite particles. The prepared electrode was tightly attached to the membrane without mechanical pressing and heat treatment. The electrode composition, i.e., the ratio between Pt-Ru/C and ionomer in the electrode, was controllable by Nafion content in the suspension, and strongly influenced on the DMFC performance. Accordingly, the anode with ionomer fraction of 26% exhibited the highest performance, which was more than twice as high as the performance attained in a standard electrode fabrication (hot press method).

Abstract: The most effective geometry for design electrode and the advantage of low cost equipment in ultrasonic-aided electrochemical finishing for a freeform surface following turning machining was investigated. The proposed design process used an effective electrode instead of the mate electrode as in conventional ECM. Hence higher electrical current is not required when the effective design electrode is used to reduce the response area. Through simple equipment attachment, electrochemical finishing can follow the traditional cutting on the same machine. The controlled factors included the chemical composition and concentration of the electrolyte, the initial gap width, the flow rate of electrolyte, workpiece rotational speed, and die material. The design electrode is primarily discussed among the factors affecting the electrochemical finishing. The experimental parameters were current rating, electrode feed rate, frequency , power level of ultrasonics, and electrode geometry. The effective design electrode with small wedge angle and small edge rounding radius had an optimal value for higher current density and provided larger discharge space, which produce a smoother surface. The electrode of globe-shape with small radius performed best in the finishing process. The electrochemical finishing needed only a short time to make the workpiece smooth and bright and save the need for the precise process of traditional machining. The ultrasonic-aided electrochemical finishing is recommended for the finishing process of the freeform surface.

Abstract: This study discusses electrochemical finishing of female screw using different types of completely inserted electrodes as well as feeding electrodes for die material. In the experiment, four types of design electrode are completely inserted and put through both continuous and pulse direct current and another four types of electrode are used with the application of continuous direct current and axial electrode feed. The controlled factors include the chemical composition and the concentration of the electrolyte, the electrolyte temperature, the flow rate of electrolyte, rotational speed of the electrode, current density, and current rating. The parameters are electrolytic time, die material, pulse period, feed rate of the electrode, and electrode geometry. For inserted electrodes, an electrode with thin plate provides more sufficient discharge space, which is advantageous for polishing. The electrode of single plate performs better than the double plate. Pulse direct current can promote the effect of electrochemical finishing, but the machining time is longer and the cost is raised. For feeding electrodes, an electrode of one side borer tip and thinner heavy section performs the best polishing effect in the current investigation. The electrochemical finishing after screw cutting just needs quite short time to make the surface of female screw smoothing and bright.

Abstract: This research presents a new modus of electrochemical finishing as a finish process using an effective design of forming sheet electrode on zinc alloys beyond traditional process of die casting on the surface of castings instead of the conventional hand or machines polishing. In the current experiment, the author takes an outer shell of toy vehicle for instance; five types of design electrode are used and supplied with continuous direct current in the experiment of electrochemical finishing. For the design electrodes, a thin plate with small end radius and small wedge angle are associated with higher current density and provides larger discharge space and better polishing effect. The electrode with spherical head performs the best. The electrochemical finishing after die casting saves the need of hand or machines polishing just needs quite short time to make the surface of castings smoothing and bright. An effective and low-cost polishing of the surface of castings is presented.