Invited speakerS of ICMMT 2018

Prof. Yu-Lung Lo, National Cheng Kung University, Taiwan

Yu-Lung Lo received his B.S. degree from National Cheng Kung University, Tainan, Taiwan, R.O.C., in 1985, and his M.S. and Ph.D. degrees in Mechanical Engineering from the Smart Materials and Structures Research Center, University of Maryland, College Park, USA, in 1992 and 1995, respectively. After graduation, he joined the Opto-Electronics and Systems Laboratories of the Industrial Technology Research Institute (ITRI), working on fiber-optic smart structures and fiber communications. He has been faculty of the Mechanical Engineering Department, NCKU, since 1996, where he is now a full professor and distinguished professor, and also an affiliate professor in Institute of Nanotechnology and Microsystem Engineering. He now is director of Instrument Development Center at NCKU.
Dr. Lo received Research Excellence in Institute of Engineering from NCKU in 2007, the First-Class Research Award from NSC in 2005/2006, A-Class Research Award by NCKU in 2006, and the Dr. Ta-You Wu Award for Young Researchers from NSC in 2002. Also, his students won Bronze Award on Competition in Mechanical Engineering Master Thesis issued by HIWIN TECHNOLOGIES CORP., World Leader in Linear Motion and Control Technology in 2006 and Golden Award on Competition in Opto-electric System Design in 2008. Dr. Lo was included in the Who's Who in the World, Who's Who in Science and Engineering lists, and the International Directory of Distinguished Leadership.
He was invited to be an invited speaker, keynote speaker, and plenary speaker in the optics related international conferences, and also organized and chaired section of international conferences. He was chair of the technical division of optical methods from 2007 to 2008 in the Society of Experimental Mechanics (SEM) in the USA. Now he is Chairman of Asian Society of Experiment Mechanics (ASEM) and General Chair of International Symposium on Optomechatronic Technology, 2017. His research interests include 3D printing, optomechatronics, experimental mechanics, fiber-optic sensors, optical techniques in precision measurements, and biophotonics. He has authored over 150 journal publications and has filed for several patents. One of his articles is included in Spotlight on Optics by OSA in 2015. Now he is member of Society for Experimental Mechanics (SEM). Citation Number: 3033/H-Index: 33/i10 Index: 89 (Google Scholar).
Speech title: Optimized Manufacturing Parameters for 3D Selective Laser Melting System-Verified by Experiments
Abstract: Abstract: The simulations are based on a new volumetric heat source which takes into account the effect of the powder size distribution on the propagation of the laser energy through the depth of the metal powder layer. Three-dimensional finite element heat transfer simulations with new volumetric heat source are performed to estimate the size of the melt pool cross-section during Selective Laser Melting (SLM). It shows that the peak melt pool temperature obtained in the present simulations (3005 K) lower than the evaporation point of the powder particle layer is in better agreement with the experimental data than that obtained in previous simulation studies. In this study, a pyrometer used to measure the peak temperature of the melt pool is also studied for an on-line monitoring in a 3D SLM system. Additionally, the proposed finite element heat transfer model has been used to predict the stability of single SLM scan melt tracks produced under various laser powers and scanning speeds. It shows that the prediction results are consistent with the experimental observations. Finally, simulations are performed to predict the stability condition of a single scan melt track in the SLM process with different parameters in manufacturing such as laser power, scanning speed, powder distribution, layer thickness, and etc. As a result, the prediction of some conditions in optimization are consistent with the experimental findings.

 

Assoc. Prof. Jakrapong Kaewkhao, Nakhon Pathom Rajabhat University, Thailand
Assoc.Prof.Dr.Jakrapong Kaewkhao received Ph.D. degree in physics from King Mongkut’s University of Technology Thonburi (KMUTT), Thailand, in 2008. He attended a postdoctoral short course research of an X-rays induced luminescence study in glasses, supervised by Prof.Dr.HongJoo Kim, at KyungPook National University (KNU), Korea, in 2012. In the same year, he has been awarded as the best alumni of Silpakorn University, Thailand. Through his academic career, his research interests involve glass scintillators, Ln3+ doped in glasses for luminescence applications, color glasses, radiation shielding glasses (gamma and neutron), natural gemstone enhancements, and imitation jewelry from glasses. His research on imitation jewelry from glasses has been awarded by several national organizations, e.g., Thailand Research Fund (TRF), National Innovation Agency (NIA), The Science Society of Thailand (SST), and National Research Council of Thailand (NRCT). His recent work focuses on the development of imitation of color-changed gemstone for ornament products, and has recently been awarded by National Research Council of Thailand (NRCT) in 2015. This project has also been awarded the Best Innovation Awards by the 43rd International Exhibition of Innovation of Geneva, Switzerland, and the Medaille D’Argent Silver Medal Silbermadaille in 2015 and Seoul International Invention Fair in 2016. Recently, He has been awarded by National Research Council of Thailand (NRCT) in 2017 from research project "Development of lead free glass for radiation shielding material".

Currently, he is director of the Center of Excellence in Glass Technology and Materials Science (CEGM), Nakhon Pathom Rajabhat University (NPRU), Thailand. He has handled 60 research projects in glass science and technology, radiation physics, and gemstone enhancements (principal investigator 32 projects). He is a member of AMoRE collaboration (Advanced Molybdenum Based Rare Experiment), to search mass of neutrinos, which supported by Institute for Basic Science (IBS, Korea). He has published 247 papers in international journals, 955 citations and H-index = 16 (Data obtained from Scopus). He has also been a reviewer of 25 international journals, and a member of the international radiation physics society (IRPS). He has frequently been the keynote/invited speaker in many international conferences on physics and related topics in different countries, e.g., Thailand, Korea, India, Laos, and Indonesia. During 2014-2017, he was visiting professor at Radiation Science Research Institute, KyungPook National University (Korea), at Institut Teknologi Sepuluh Nopember, at Institut Teknologi Sumatra (Indonesia) and at Sri Venkateswara University, India. In 2016, he was guest scientist at department of physics, KyungPook National University (KNU), Korea (Supported by 2016 NRCT - NRF Scientist Exchange Program). Apart from his academic involvements, he is currently a consultant for color glass production and gemstone enhancements in glass and jewelry businesses.

Speech Title: Non-Proportionality Study of CaMoO4 and GAGG:Ce Scintillation Crystals using Compton Coincidence Technique (CCT)

Abstract: In this study, the CCT technique and nuclear instrument module (NIM) setup for the measurements of coincidence electron energy spectra of calcium molybdate (CaMoO4) and cerium doped gadolinium aluminium gallium garnet (Gd3Al2Ga3O12:Ce or GAGG:Ce) scintillation crystals were carried out. The 137Cs irradiated gamma rays with an energy (Eγ) of 662 keV was used as a radioactive source. The coincidence electron energy spectra were recorded at seven scattering angles of 300-1200. It was found that seven corresponding electron energies were in the range of 100.5-435.4 keV. The results show that, for all electron energies, the electron energy peaks of CaMoO4 crystal yielded higher number of counts than those of GAGG:Ce crystal. The electron energy resolution, the light yield and non-proportionality were also determined. It was found that the energy resolutions are inverse proportional to the square root of electron energy for both crystals. Furthermore, the results show that the light yield of GAGG:Ce crystal is much higher than that of CaMoO4 crystal. It was also found that both CaMoO4 and GAGG:Ce crystals demonstrated good proportional property in the electron energy range of 260-435.4 keV.
 

 

 

Prof. Kei Ameyama, Ritsumeikan University, Japan
Prof. Dr. Kei Ameyama was born in Komatsu, a coastal city in mid-west Japan. He studied Materials Science at Kyoto University and after completing his PhD he joined the Department of Mechanical Engineering at Ritsumeikan University, as an Assistant Professor. In 1989, he spent a year as a visiting scientist at the University of Toronto. He has since continued to pursue a career at Ritsumeikan University, becoming a Professor at the Department of Mechanical Engineering in 1996, Chairperson of the Department in 1997, Vice Dean of the Faculty of Science and Engineering from 2007 to 2010. In 2009, he was appointed a board member of the Japan Institute of Metals, and a vice president of the Japan Society of Powder and Powder Metallurgy since 2016. He also works as a committee member for the Iron and Steel Institute of Japan and the Society of Materials Science of Japan. He took up position as head of the Nano-Structure and Powder Technology Research Center at Ritsumeikan University in 2010. In the same year he also became a Project Leader of Industry–Academia Collaborative R&D Programs funded by the Japan Science and Technology Agency, JST. Through the JST research project, he invented an innovative structure material "Harmonic Structure Designed Materials". The key idea is the creation of a continuous three-dimensional network of hard ultrafine-grained skeleton filled with islands of soft coarse-grained regions. And, the harmonic structure materials solved the strength–ductility tradeoff paradox.

Speech Title: Harmonic Structure : An Innovative High Performance Metallic Materials Design

Abstract: A heterogeneous microstructure consisting of bimodal grain size together with a controlled and specific topological distribution of nano- and meso- grains is quite important to improve mechanical properties of structural metallic materials. The harmonic structure design is one of the heterogeneous microstructure design, and it is heterogeneous on micro- but homogeneous on macro-scales. In the present work, the harmonic structure design has been applied to pure-Ti, Ni, Cu, Fe, Ti-6Al-4V alloy and SUS304L stainless steel via a powder metallurgy route consisting of controlled severe plastic deformation of the corresponding powder via mechanical milling or high pressure gas milling, and subsequent consolidation by SPS. At a macro-scale, the harmonic structure materials exhibited significantly better combination of strength and ductility, under quasi-static loadings, as compared to their homogeneous microstructure counterparts. The comparison of mechanical properties of various metals and alloys with HS and their coarse-grained (CG) counterparts revealed that the normalized yield strength of the HS metals and alloys was considerably higher as compared to their CG counterparts. Since the area under the stress-strain curve is considered as a representation of the toughness of a material, the HS materials also exhibited improved toughness. This behavior was essentially related to the ability of the harmonic structure to promote the uniform distribution of strain during plastic deformation, leading to improved mechanical properties by avoiding or delaying localized plastic instability. In other words, the characteristic “micro-scale stress concentration” and “macro-scale stress dispersion” by the Shell-network structure are assumed to lead a large work hardening and a constraint of the deformation localization.