Segregation in bimetallic alloys and its influence on wetting on a positive temperature coefficient resistor BaTiO₃ ceramic

Bimetallic alloys have been considered in terms of their wetting behavior on semiconducting BaTiO₃. In an earlier study, wetting behavior was strongly linked to ohmic contact behavior. However, the wetting behavior does not always correlate in the form of high work of adhesion-low contact resistance. The departure from this trend is associated with the nature of the segregation of the solute. Two extreme cases are considered in this study: no driving force for segregation and a strong driving force. These cases are characterized with sessile drop experiments and qualitatively analysed in terms of thermodynamic analysis, both a surface enrichment model is considered together with an energy diagram approach. Both models give excellent qualitative agreement to the observed wetting behavior of the bimetallic alloy-BaTiO₃ system.