Seminar on “Thermochemical nanomachining of diamond"
Speaker: Prof. Jiwang Yan
Date: 18 April 2018 (Wednesday)
Venue: CF 401
(This seminar is open to the public.)
Prof. Jiwang Yan obtained his Ph.D. from Tohoku University in 2000 and is currently a professor of Mechanical Engineering at Keio University, Japan, leading the Laboratory for Precision Machining and Nano Processing (PMNP). His research areas include ultraprecision machining, micro/nanomanufacturing, material processing, and nanomechanics. His lab explores multidisciplinary R&D by interfacing manufacturing technology with mechanical science, material science, nanoscience, chemistry, and physics. His research has been especially focused on the machining of hard and brittle materials, such as silicon, germanium, silicon carbide, diamond, glass, ceramics and composites. He has led the implementation of tens of research projects supported by governments and industry to develop key fabrication processes for optics, molds, cutting/grinding tools, semiconductor substrates, battery electrodes, and biomechanical components. He has received a few tens of awards from academic societies and scientific foundations for his contributions in research. He is now a member of the Japan Society of Mechanical Engineers (JSME), Japan Society for Precision Engineering (JSPE), Japan Society for Abrasive Technology (JSAT), Japan Society for Applied Physics (JSAP), American Society for Precision Engineering (ASPE), European Society for Precision Engineering and Nanotechnology (euspen), and the International Academy for Production Engineering (CIRP). He also serves on the editorial boards for several academic journals, such as the International Journal of Machine Tools and Manufacture (IJMTM), Nanomanufacturing and Metrology, and Applied Science.
Diamond is an extremely important material for manufacturing cutting tools, power electronic substrates, and optical components. Due to its extremely high hardness, diamond is very difficult to machine by conventional mechanical methods. In this talk, high-quality machining of diamond through thermo-chemical approaches will be focused. Two key technologies recently developed by the speaker’s group will be highlighted. The first is the micromachining technology for polycrystalline diamond by electrical discharge machining using a special electrode material which promotes graphitization and carbon diffusion of diamond surface under electrical discharge-induced heating effects. The second is a nanostructure imprinting technology for single-crystal diamond, which is based on thermochemical reaction between diamond and a micro-structured transition metal mold under high-temperature and high-pressure pressing. These two thermochemical machining methods have been demonstrated to be cost-efficient for fabricating high-precision micro/nanostructures on diamond materials.