Controlling microstructure via thermal science analysis during resistance spot welding

7^th Annual Congress on Materials Research and Technology

February 20-21, 2017 Berlin, Germany

Peng-Sheng Wei and Tzong-Huei Wu

National Sun Yat-Sen University, Taiwan

Scientific Tracks Abstracts: J Material Sci Eng

Abstract :

Resistance spot welding is an important technique often used in joining thin workpieces in various aerospace, automobile and manufacturing technologies. The process involves complicated magneto-fluid dynamics, heat transfer, metallurgy, physics and chemistry, etc. This presentation theoretically and quantitatively investigates and interprets processes by realistically accounting for transient magneto-fluid mechanics, heat and species transport, and bulk resistance in workpiece, and film and constriction resistances at contact interfaces. Contact resistances are functions of temperature, hardness, contact spots, etc. Since temperature gradient and solidification rate are found, the computed morphological parameter reflecting constitutional supercooling shows that different microstructures such as planar, columnar microstructures, columnar dendrite, equiaxed grains of the weld nugget can be interpreted, predicted and controlled.

Biography :

Peng-Sheng Wei received Ph.D. in Mechanical Engineering Department at University of California, Davis, in 1984. He has been a professor in the Department of Mechanical and Electro-Mechanical Engineering of National Sun Yat-Sen University, Kaohsiung, Taiwan, since 1989. Dr. Wei has contributed to advancing the understanding of and to the applications of electron and laser beam, plasma, and resistance welding through theoretical analyses coupled with verification experiments. Investigations also include studies of their thermal and fluid flow processes, and formations of the defects such as humping, rippling, spiking and porosity. Dr. Wei has published more than 80 journal papers, given keynote or invited speeches in international conferences more than 80 times. He is a Fellow of AWS (2007), and a Fellow of ASME (2000). He also received the Outstanding Research Achievement Awards from both the National Science Council (2004), and NSYSU (1991, 2001, 2004), the Outstanding Scholar Research Project Winner Award from National Science Council (2008), the Adams Memorial Membership Award from AWS (2008), the Warren F. Savage Memorial Award from AWS (2012), and the William Irrgang Memorial Award from AWS (2014). He has been the Xi- Wan Chair Professor of NSYSU since 2009, and Invited Distinguished Professor in the Beijing University of Technology, China, during 2015-2017.

Email: pswei@mail.nsysu.edu.tw