Papers by Author: Ming Huan Wang

Abstract: A method of fabricating convex plate-shaped micro electrode was proposed based on the electrochemical etching principle. The square sectional electrodes were prepared in advanced using wire-EDM, The micro cylindrical electrode was fabricated firstly by using the eletrochechemical etching method. Then the top end was insulated to protect it from etching. Then the convex plate-shaped micro electrode was obtained in subsequent etching. Comparative experiments in drilling micro-hole in stainless steel with the thickness of 1mm were done by using the cylindrical and convex plate-shaped micro electrode. Results shows that the better locality, smaller side-gap and hole taper could be obtain by using convex plate-shaped micro electrode.

Abstract: Micro-electrode preparation is the key technology in micro-machining of micro- mechanics and micro-parts. In this research, the machining method of micro-pin using micro-electrochemical machining (micro-ECM) was proposed. The principle of micro-pin fabrication is introduced and the studies are focused on the effects of varies parameters on the shape of the micro-pin. The theoretic model between the shape of micro-pin and the parameters including power, voltage, duty ratio of pulse power, immerge depth of electrode is built up and then verified by experimentations. Experimental results denote that the micro-electrode with desirable shape and size could be prepared by controlling applied parameters. When the immersing depth is deeper, the pulse power, low voltage and duty ratio is proper selected. On the contrary, the DC power or pulse power with higher voltage and duty ratio should be applied. Finally, micro-pin with diameter of 5μm and 60μm long was fabricated when the DC power of 1.8V voltage and immersing depth of 1mm is applied.

Abstract: Due to the mutual radiation impedance may influence acoustics performance of a broadband dense plane array seriously, the expression of mutual radiation impedance among the transducers is developed according to the definition of mutual radiation impedance based on BEM（Boundary Element Method）. BEM model is established for acoustic radiation of a broadband dense plane array with nine elements. Sound pressure distribution of the nine-element array is solved using SYSNOISE software. And mutual radiation impedances are calculated on the condition of knowing surface normal velocity. Acoustic performance of the nine-element array is analysed through mutual radiation impedance. The influence of mutual impedance on acoustics performance for nine-element array is verified by comparing with measured curve of transducer conductance. The results show that it is successful to calculate mutual impedance of the array and predict acoustics performance using BEM.

Abstract: In this study the prediction of the erosion profiles during ECM of the spiral hole was presented. By assumptions, the major points were simplified into one-dimensional problems. The theoretical and computational model was built to illustrate the profile movement as the time elapses. The analysis was based on the law of electrolysis and the software MATLAB was used. Verifications were done through experiments and the deviation was 7.5% between theoretical and experimental result. On the basis of the prediction of the erosion profile, the applied parameters could be estimated.

Abstract: Electrochemical machining (ECM) technology has the advantage of machining the workpiece with complex profile on the basis of electrolysis. In this study, turbulated holes with the rib’s shape of spiral and annular were processed by ECM by using the shaped cathodes. Experimental system was built which consists of electrolyte supply module, power supply unit and workpiece holding device. Machining experimentations were carried out on the built system. Analysis and discussions were done according to the experimental results. It indicated machining efficiency is high by using the shaped cathode. Machining error could be controlled within 10-20%.

Abstract: The numerical simulation and experiment had been applied to study the cooling of electric cutting tool. Temperature and wind velocity vector of three-dimensional cooling duct were obtained by Fluent. From the numerical simulation, the stagnation flow, reflow and backset which resulted in the poor cooling condition of the electric cutting tool were discussed. By modifying ribs, partition and outlet, a new cooling duct was reconstructed. The cooling effect of the new cooling duct was better than the original one by the experiment test.

Abstract: Diamond wire saw is the leading technology for use in slicing hard brittle material. This paper provides a brief review of its research progress in the most recent years. According to the bonding material kinds of diamond wire saw, it can be classified into three main categories, i.e. metallic bonding materials, organic bonding materials, and resin bonding materials. In the past decade, several new major technical developments in fixed abrasive diamond wire saw have emerged. This paper investigates the related literature on four different types of fixed abrasive diamond wire saws, presents their manufacturing processes and machining performance, and compares the tension and anti-abrasion of the wire saws, removal efficiency of slicing, and their applications in silicon slicing.

Abstract: Diamond wire saw is the leading technology for use in cutting hard brittle material. Its smaller kerf and faster cutting time make it replacing the conventional slurry technology for those materials. Turned over the traditional router, this paper presents a novel approach that replaces the typical metallic core with a nonmetallic core, for manufacturing of ultraviolet curing resin fixed-abrasive diamond wire saw (DWS). The experiments show that the diamond wire saw made by this manufacturing method can obtain a good performance as well as taking many other advantages.

Abstract: The machining of materials on microscopic scales is considered to be great importance to a wide variety of fields. Electrochemical Micro-machining (EMM) appears to be promising to machine the micro-structures in future due to the material is dissolved at the unit of ion. This paper is focused on developing a micro electrochemical machining system in which the micro-structures such as micro-cylinder, multiple micro-electrodes, micro-holes and micro-slot were processed. The micro-electrodes were prepared in a precisely controlling the electrochemical etching process. Mathematical model controlling the diameters of electrodes was built up. Furthermore, the obtained micro-electrodes were selected as the cathode tool for micro holes drilling and micro-slot milling using pulse power in Micro-ECM.