Influence of substrate orientation on wetting kinetics in reactive metal/ceramic systems
- Domaine Univ., Saint Martin d`Heres (France). Lab. de Thermodynamique et Physico-Chimie Metallurgiques
It is expected that crystallographic factors, like the orientation of the substrate surface, which can affect reaction kinetics, can also influence wetting kinetics. The effect of substrate orientation will be studied in two systems. The first one is a Cu-Ti alloy on {alpha}-monocrystalline alumina. For this system, wettability and reactivity of Cu-Ti alloys of various compositions on Al{sub 2}O{sub 3} monocrystals of random orientation were studied in detail by Kritsalis et al. A two-step wetting process was observed: after a very rapid decrease of contact angle in less than one second, explained by the formation of an adsorption layer of Ti at the interface, a much slower decrease arises in about 10{sup 2}s, attributed to the formation of the wettable Ti monoxide at the interface. In the present study, sessile drop experiments are carried out with a specific alloy composition (Cu-10.8 at.% Ti) on three different crystallographic faces of alumina, as well as on surfaces of random orientation. The second system investigated here is pure Al on carbon. Wetting and interfacial reactions have already been studied by Landry et al. on vitreous carbon. After a first decrease of contact angle owing to deoxidation of the Al drop and Al{sub 4}C{sub 3} formation in transient conditions, a quasi-stationary regime of carbide growth at the triple line is established, leading to a linear variation of the drop base radius as a function of time. In the present work, sessile drop experiments are performed on other varieties of carbon, i.e., pyrocarbon and pseudo-monocrystalline carbon.
- OSTI ID:
- 413258
- Journal Information:
- Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 11 Vol. 35; ISSN 1359-6462; ISSN SCMAF7
- Country of Publication:
- United States
- Language:
- English
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