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Wettability of Aluminum–Magnesium Alloys on Silicon Carbide Substrates
Author(s) -
Candan Ercan,
Atkinson Helen V.,
Turen Yunus,
Salaoru Iulia,
Candan Sennur
Publication year - 2011
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.1551-2916.2010.04157.x
Subject(s) - wetting , materials science , contact angle , silicon carbide , sessile drop technique , magnesium , substrate (aquarium) , composite material , oxide , aluminium , silicon oxide , silicon , evaporation , metallurgy , alloy , liquid metal , adhesion , silicon nitride , oceanography , physics , thermodynamics , geology
Wettability between the liquid matrix and the reinforcement is important for the processing of metal matrix composites; the contact angle can be measured with the sessile drop method. However, for the wetting angle of liquid Al–Mg alloys on ceramics, it is difficult to obtain an accurate measurement because aluminum is easily oxidized and the rate of evaporation of Mg is high. Here, an oxide‐stripping device is used to provide an aluminum alloy droplet with minimal oxide on the surface when the droplet makes initial contact with the substrate. Results are reported for contact angle (θ) versus time for Al–2.1, 3.9, 9.1, and 14.2 wt% Mg alloys with sintered silicon carbide substrates. The samples were quenched from the test temperature. Magnesium plays a key role in the adhesion, or otherwise, of the droplet to the substrate. Magnesium is probably migrating to the surface of the droplet and evaporating or forming a “crusty” layer on the surface over time. When viewed from above, “halo” regions, initially showing interference colors, develop on the substrate around the base of the droplets. These are probably associated with Mg (and Al) diffusing from the droplet across the surface of the substrate.