时间：2014年3月21日下午三点
地点：基础楼301
参加人数： 30
报告题目：Thermal Analysis and Control of Defects Occurred during High-Intensity Beam Welding Process
大师简介

Dr. 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, China, since 1989. Dr. Wei has contributed to advancing 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 70 journal papers. 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), Adams Memorial Membership Award from AWS (2008), and Warren F. Savage Memorial Award from AWS（2012）

内容简介
This presentation analyzes defects of (1) surface rippling and humping, (2) root spiking, (3) pore formation, and (4) missed joint due to thermoelectric magnetism in electron beam keyhole welding. The defects of rippling, humping, spiking, porosity and missed-joint seriously reduce the properties and strength of the joint and products. We measure, analyze and confirm mechanisms of these defects. Controlling of these defects becomes achievable.

学生反响

本报告采用定量计算和实际试验测量相结合的方法从热力学角度对电子束穿孔焊接时形成的波纹、驼峰、错边、熔池根部尖峰及气孔等缺陷进行了对比分析，研究了焊接工艺对以上缺陷形成的影响，揭示了缺陷的形成机理，实现了缺陷的可控性。参加报告会的有相关专业的老师和博士、硕士研究生。大家对于Prof. Wei的报告非常感兴趣，就高能束焊接时小孔形成的热力分布以及激光-电弧复合焊接的发展前景等方面提出了专业问题，魏教授都做了详尽的解答，在理论分析与实际试验相结合的研究手段方面同学们获益匪浅。