Seminar - Metal Additive Manufacturing (3D Printing): CFD Analysis and Design of Powder-Fed Laser Cladding by Prof. Hsin-Luen Tsai
日期：2017 年 01 月 24 日 ( 星期二)
Time：2:30 pm – 3:30 pm
Laser cladding technology is to deposit a clad layer covering on the surface of substrate, in order to achieve enhanced corrosion and wear properties by supplying powder or wire. The quality of the gas powder stream and interaction among gas jet, powder jet and laser beam determine the substrate cladding quality, powder utilizing efficiency and the shielding of the melt area in the powder-fed laser cladding. This lecture will deliver a brief introduction of 3D metal additive manufacturing, the usage of CFD tool to aid the analysis and design for metal powder feeding process and to analyze the gas powder stream and interactions among particles, gas flow and laser thermal source. The powder focus and surrounding flow structure evolution are predicted under conditions closer to the experimental processing environment. Particle laser heating mainly depends on the laser power levels as well as the residence time in the heating zone. And the flow structure and particle velocities determine the particle location, distribution, and residence time. The selection of particle absorptivity is very crucial in numerical modelling. The generation of novel expression of temperature-dependent particle absorptivity is urgently needed for process prediction of laser cladding in the near future. Physically, the particle absorptivity could be treated as the synthesis of particle reflectivity, absorptivity, and laser attenuation. Future experimental works are needed to measure the powder laser energy absorption rate and provide the experimental results for facilitating numerical models to select proper particle absorptivity. Furthermore, that aims to develop the laser cladding industrial database, which contains material type, powder size, particle absorptivity and related parameters.
Prof. Tsai received his Bachelor degree from the Department of Aeronautical engineering at the Feng-Chia University in 1993 and Master and PhD degree from the Department of Aeronautics and Astronautics at National Cheng Kung University (NCKU), Taiwan in 1995 and 2001 respectively. He worked at NCKU as a postdoctoral Research Fellow from Oct. 2001 to Oct. 2005 and then continued his teaching and research works at the Department of Electronic Engineering (Aviation Section) at the Kao-Yuan University, Taiwan. He was promoted to Associate professorship in Aug. 2015. He had been the Leader of Registration Section, School of Continuing Education from Nov. 2011 to May 2014 in the Kao-Yuan University, Taiwan. Tsai has authored and co-authored many scientific papers, and conference papers. He was also awarded 7 patents and some professional certificates. His current research interests are in the areas of (1) IC Engine Modeling and CFD aided Design (with Kymco and Luxgen), (2) Fuel Atomization, Droplet and Spray Combustion Modeling, (3) Green Hybrid Rocket Propulsion and Sounding Rocket Experiments (with NCKU ASTRC), (4) Metal Additive Manufacturing (3D Printing): Powder-fed Laser Cladding (with ITRI, Tainan campus, Taiwan), (5) Nanotechnology & Semiconductor manufacturing (Field Emisson Display and Nano-Thermoelectrics) (with NDL, Tainan, Taiwan), (6) UAV and Quadcopter Design and Operations (participated in UAV competition), and (7) Aircraft Maintenance (National Certificate Training).