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Transitions in Wetting Behavior Between Liquid Ag – CuO Alloys and Al 2 O 3 Substrates
Author(s) -
Friant Jared R.,
Meier Alan,
Darsell Jens T.,
Weil K. Scott
Publication year - 2012
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2012.05094.x
Subject(s) - wetting , miscibility , chemistry , materials science , substrate (aquarium) , chemical engineering , polymer , composite material , oceanography , engineering , geology
The study reported here examines wetting between A l 2 O 3 and a series of A g– C u O air braze filler metals. Based on in‐situ contact angle measurements, two transitions in wetting behavior were identified in the composition range of 0–40 mol% C u O . The first transition occurs directly at the miscibility gap boundary composition (for a given temperature) of the A g– C u O phase diagram and is attributable to the presence of two liquid phases, one of which is rich in copper oxide and preferentially wets the alumina substrate via the mechanism predicted by Cahn's critical point wetting theory. The second transition occurs at a filler metal composition that falls well within the miscibility gap for the A g– C u O system and may occur due to the formation of a reaction product between the substrate and the molten filler metal, as denoted by small, discontinuous reaction regions.