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Wetting of Cu substrates with micrometer and nanometer grains by molten Sn‐3.5Ag‐0.7Cu alloy
Author(s) -
Shen Ping,
Yin Zhongfa,
Yang Jun,
Sun Jianxin,
Jiang Zhonghao,
Jiang Qichuan
Publication year - 2010
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.3345
Subject(s) - kirkendall effect , wetting , micrometer , nanometre , materials science , alloy , nanocrystalline material , microstructure , nanotechnology , metallurgy , chemical engineering , composite material , physics , engineering , optics
Wetting behaviors and interfacial microstructures of molten Sn‐3.5Ag‐0.7Cu drops on micrometer‐ and nanometer‐grained Cu substrates were studied. The wettability of the micrometer‐grained Cu substrates was found to be better than that of the nanometer‐grained substrates. Moreover, Kirkendall voids were observed at the interface of the nanometer‐grained Cu substrates but not of the micrometer‐grained substrates. It is presumed that the nanocrystalline surfaces are more prone to adsorption of impurities, thus reducing the surface free energy. On the other hand, its atomic diffusivity is greatly enhanced. As a result, the wettability deteriorates while the Kirkendall voids readily proliferate. Copyright © 2010 John Wiley & Sons, Ltd.