New Experimental Setup for Wettability Characterization under Monitored Oxygen Activity: II, Wettability of Sapphire by Silver‐Oxygen Melts

Abstract

Wetting of silver on sapphire and surface tension of silver are both determined as a function of oxygen activity in a range corresponding to oxygen content in silver varying from 10 −12 to 10 −2 . The contact angle is shown to decrease at high oxygen activity when simultaneous decreases in surface tension of silver and interfacial energy between silver and alumina occur. This double oxygen adsorption is ther‐modynamically analyzed and some relevant parameters inducing oxygen segregation at the silver interfaces are proposed.