题目：What we should consider for full densification when sintering
主讲人：Prof. Suk-Joong L. Kang
Densification of a powder compact, the primary goal of sintering, is affected by various processing parameters, including the particle/pore size and distribution, and the thermal cycle (sintering temperature and heating rate). The effects of these parameters have been closely and widely analyzed for systems without grain growth in most cases. Sintering theories so developed can predict the densification kinetics with respect to certain processing parameters, in particular the particle size and sintering temperature. For full densification of the powder compact, however, it is essential to prevent the entrapment of isolated pores within growing grains and to retain them at the grain boundaries. Theories of microstructural evolution in porous systems have been developed in terms of the relative kinetics of densification and normal grain growth. To achieve full densification, grain growth, abnormal grain growth (AGG) in particular, must be suppressed. When AGG takes place, many isolated pores can be entrapped within growing grains, a process which limits the densification.
This presentation will discuss general directions for the full densification of powder compacts. First, we will briefly review the effects of the particle size and powder packing on densification. The effect of the thermal cycle will also be reviewed. Based on the recently established mixed mechanism principle of microstructural evolution, strategies for suppressing AGG will be presented.
Dr. Suk-Joong L. Kang is a Distinguished Professor in the Department of Materials Science and Engineering at the Korea Advanced Institute of Science and Technology (KAIST). He received a Dr.-Ing degree from the Ecole Centrale de Paris(1980), and a Dr. d’Etat degree from the University of Paris VI(1985). After joining KAIST in 1980, he also served as a Visiting Professor at the StuttgartMax-Plank-Institut (’82-’83, ’88)at Samsung Electromechanics (’93-’94), at the University of New South Wales (’01-’02) and at the University of Tokyo (’08), and as President of the Korea Institute of Ceramic Engineering and Technology (KICET) (’15-’18).
Dr. Kang has published more than 280 papers on sintering and microstructural evolution in ceramics and metals. Since 2000, he has presented over100 invited talks at international conferences.He is the author of the text Sintering: Densification, Grain Growth and Microstructure, published in 2005. He developed the “Pore Filling Theory” of liquid phase sintering.Since the late 1990’s, Dr. Kang has particularly contributed to the understanding of microstructural evolution by structural transition and defect formation at interfaces. He introduced the concept of the mixed control of boundary migration, and deduced the mixed mechanism principle of microstructural evolution. Dr. Kang is a fellow of the American Ceramic Society and a member of the World Academy of Ceramics, President-Elect of the International Ceramic Federation (’18-’20). He also served as President of the Korean Powder Metallurgy Institute (’06), the Korean Ceramic Society (’12), and the Asia-Oceania Ceramic Federation (’13-’14), and as Editor-in-Chief of the Journal of Asian Ceramic Societies (’13-’15).He is the recipient the Sosman Award from the American Ceramic Society (’11), the Richard Brook Award from the European Ceramic Society (’15), the Helmholtz International Fellow Award from the Helmholtz Gemeinschaft (Germany) (’15), the Inchon Prize from the Inchon Memorial Foundation (’07), and the Korea Engineering Prize from the President of the Republic of Korea (’10).