Biing Hwa Yan

Bio: Biing Hwa Yan is an academic researcher from National Central University. The author has contributed to research in topics: Machining & Surface roughness. The author has an hindex of 15, co-authored 24 publications receiving 1275 citations.

3D microstructuring of Pyrex glass using the electrochemical discharge machining process

Abstract: Electrochemical discharge machining (ECDM) is demonstrated to be a potential process for 3D microstructuring of Pyrex glass. However, the key to widening ECDM micromilling applications lies in how to improve the machining accuracy. To improve the machining quality of the ECDM micromilling process, microgroove machining experiments were conducted in this study. Three factors affecting ECDM micromilling performance—pulse voltage, tool rotational rate and travel rate of tool—were taken up as machining parameters to investigate their influences on machining performance. The results indicate that optimum combinations of both pulse voltage and tool rotational rate will realize better machining accuracy. The feasibility of three-dimensional microstructure machining was demonstrated by layer-by-layer ECDM micromilling machining. Complex structures were made to demonstrate the great potential for the 3D microstructuring of Pyrex glass of the ECDM micromilling process.

Enhancement of ECDM efficiency and accuracy by spherical tool electrode

Abstract: Electrochemical discharge machining (ECDM) is an emerging non-traditional processing technique that involves high-temperature melting and accelerated chemical etching under the high electrical energy discharged. However, there are still several obstacles to overcome. First, both machining time and hole entrance diameter were found to increase with increasing machining depth. In particular, the increase becomes drastic when machining depth exceeds 250 μm. In addition, achieving both high efficiency and accuracy in drilling a through hole in hard and brittle materials by ECDM poses even greater difficulty. To solve the above problems, this study proposed using a tool electrode with a spherical end whose diameter (150 μm) is larger than that of its cylindrical body (100 μm). Experimental results show that the curve surface of the spherical tool electrode reduces the contact area between the electrode and the workpiece, thus facilitating the flow of electrolyte to the electrode end, and enables rapid formation of gas film, resulting in efficient micro-hole drilling. Moreover, the curve surface does not cause excessive concentration of current density; and hence, bubbles grow at a more uniform speed; thus, increasing the discharge frequency. Comparison between machining depth of 500 μm achieved by conventional cylindrical tool electrode and the proposed spherical tool electrode shows that machining time was reduced by 83% while hole diameter was also decreased by 65%.

A review on current research trends in electrical discharge machining (EDM)

Abstract: Electrical discharge machining (EDM) is one of the earliest non-traditional machining processes. EDM process is based on thermoelectric energy between the work piece and an electrode. A pulse discharge occurs in a small gap between the work piece and the electrode and removes the unwanted material from the parent metal through melting and vaporising. The electrode and the work piece must have electrical conductivity in order to generate the spark. There are various types of products which can be produced using EDM such as dies and moulds. Parts of aerospace, automotive industry and surgical components can be finished by EDM. This paper reviews the research trends in EDM on ultrasonic vibration, dry EDM machining, EDM with powder additives, EDM in water and modeling technique in predicting EDM performances.

Micro total analysis systems: latest achievements.

Abstract: Technology 4403 Microfabrication 4403 Assembly and Interfacing 4404 Optical Integration 4405 Flow Control 4405 Standard Operations 4406 Sample Preparation 4406 Injection and Separation 4407 Fluidic Reactors 4407 Particle and Cell Sorting 4409 Cell Trapping and Culture 4409 Applications 4410 Clinical Diagnostics 4410 Nucleic Acids 4411 Proteins 4412 Cell and Tissue Studies 4413 Environmental Monitoring 4414 Literature Cited 4414