Optimization of wettability and adhesion in reactive nickel-based alloys/alumina systems by a thermodynamic approach

Optimization of wetting and adhesion in metal/oxide systems can be achieved by using solutes to control the chemistry of the interfaces and the thickness of reaction product layers. This approach is illustrated by results obtained for Ni alloy/Al2O3 systems. Wettability experiments are performed by the sessile drop technique under high vacuum or a static neutral gas atmosphere. Interfacial chemistry and morphology are determined using scanning electron microscopy and electron microprobe analysis. Adhesion is qualitatively characterized by the type of fracture observed during cooling of sessile drop samples.