Liquid-phase alloy for μEDM tools

Significance 

Recent advancement in technology has led to the development of numerous machining techniques for fabrication of different materials. For instance, in electrical and conductor devices, precision machines are required to enable fabrication of three-dimensional structures at both micro and nanoscale levels. Unfortunately, most of these machining technologies are susceptible to various failures caused by factors such as wear and tear thus hindering their functionality.

Among the commonly available micromachining technologies, micro-electro-discharge machining can be used to create microstructures in numerous applications owing to its high-precision nature. Also, it can be efficiently used for both soft and fragile materials. Generally, it is based on thermal erosion of the material due to the generated electrical discharge between the workpiece and the electrode to remove the materials from the surface. Unfortunately, the machining process is associated with several limitations like electrode wear and poor surface quality.

However, the significance of the machining electrode in determining the precision of micro-electro-discharge machining have attracted the interest of many researchers. For example, wire electro-discharge grinding is capable of achieving precise shaping of microcylindrical electrodes. On the other hand, variation in the diameter accompanied during the process reduces the quality and precision of the process. The gradual change of the electrode shape during the machining process also results in erosion which further leads to loss of part geometry and accuracy. To this mote, significant effort has been directed towards investigating, predicting and compensating electrode wear in the micro-electro-discharge machining process.

Recently, Dr. Ruining Huang and Dr. Wenbin Yu from Harbin Institute of Technology in collaboration with University of British Columbia scientists: Dr. Ying Yi and Professor Kenichi Takahata investigated the use of liquid alloy as a machining electrode in micro-electro-discharge machining process to overcome the factors influencing the electrodes wear during machining. The process was based on supplying the liquid electrode to a metallic microcapillary nozzle to eliminate electrode wear. Furthermore, scanning mode patterning and controlled discharge generation were demonstrated using microfluidic Galinstan electrodes. Their main aim was to address the electrode wear problem so as to advance the micro-electro-discharge machining technology. The work is published in Journal of Materials Processing Technology.

The authors observed the capability of using Galinstan as an electrode material for the micro-electro-discharge machining to create discharge pulses for microscale removal of materials from the sample surfaces because it is a non-toxic liquid alloy. Consequently, they successfully demonstrated arbitrary patterning on the silicon substrates due to the minimized contamination of the processed workpiece. Furthermore, the patterned linewidth generally depended on the discharge conditions. Therefore, it could be tuned without having to replace the nozzle.

The study successfully developed a microfluidic electrode for micro-electro-discharge machining based on the liquid-phase alloy. Owing to its efficiency and effectiveness, the developed method can be used to rapidly produce micropatterns at relatively low cost. Therefore, the authors are optimistic that it will help advance future development aimed at improving the micro-electro-discharge machining resolution, control and accuracy. This will ensure the production of high-quality structures for various applications.

Liquid-phase alloy for μEDM tools - Advances in Engineering

About the author

Ruining Huang is Associate Professor in the School of Mechanical Engineering and Automation of Harbin Institute of Technology, Shenzhen. He graduated from the School of Mechanical Engineering, at the Harbin Institute of Technology (2000), where he also earned his MS (2002) and PhD (2006). In 2007, he joined the Materials Science and Engineering Department at the Tsinghua University as a postdoctoral researcher. He was a Visiting Fellow at the University of British Columbia, CA, from 2015 through 2016.

His research focuses on micro/nano manufacturing field. The current research activities relate to fundamental research on micro EDM and ECM and their hybrid process, development of EDM drill and EDM/ECM process and equipment for turbine blisk of aero engine, as well as design and fabrication of microfluidic devices. Details of his work can be found in his website linked above.

About the author

Ying Yi is a post-doctoral fellow with the department of Electrical and Computer Engineering, University of British Columbia. He received the MS degree from the Department of Electronics and Radio Engineering, Kyung Hee University in 2010, and then received the PhD degree in electrical engineering from the University of British Columbia in 2016. His research interests are Micro-electronics, RF wireless systems and circuits.

About the author

Wenbin Yu is lecturer in the School of Electrical Engineering and Automation of Harbin Institute of Technology. He graduated from the School of Electrical Engineering, at the Harbin Institute of Technology (1999), where he also earned his MS (2001) and PhD (2005). He joined the Department of Electrical Engineering of North China Electric Power University as a postdoctoral researcher in 2005. He was a Visiting Scholar at the University of British Columbia, CA, from 2015 through 2016. His research interests include optical current/voltage measurement techniques and instrumentation, smart grid, relay protection and power system and its automation.

About the author

Kenichi Takahata is an Associate Professor in the Department of Electrical and Computer Engineering, UBC, as well as a Tier-2 Canada Research Chair in Advanced Micro/Nanofabrication and MEMS (micro-electro-mechanical systems). He received is BS in physics from Sophia University, Tokyo, Japan, in 1990 and his MS and PhD in electrical engineering from the University of Michigan, Ann Arbor, USA, in 2004 and 2005, respectively. He was a Visiting Scientist at the University of Wisconsin-Madison, USA, from 1999 through 2001.

Dr. Takahata held various industrial research positions for over ten years at Panasonic in Japan as well as 3M in USA before joining UBC. His research focuses on a broad range of fabrication and packaging in the micro and nano domains and their application to MEMS and other micro/nanomachined devices. Details of his work can be found in his website linked above.

Reference

Huang, R., Yi, Y., Yu, W., & Takahata, K. (2018). Liquid-phase alloy as a microfluidic electrode for micro-electro-discharge patterning. Journal of Materials Processing Technology, 258, 1-8.

Go To Journal of Materials Processing Technology

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