Influence of Oxygen Partial Pressure and Oxygen Content on the Wettability in the Copper–Oxygen–Alumina System


  • R. Raj—contributing editor

  • Supported by Volkswagenstiftung under Contract No. VW I/70079.


The influence of oxygen on the wetting behavior of copper on single-crystal Al2O3 has been studied. By controlling the oxygen partial pressure (pO2) and oxygen content in the copper simultaneously, contact angle can be varied between 125° and 22°. Evaluation of the Gibbs adsorption equation for the liquid/solid interface at 1300°C suggests that adsorption of a Cu-O complex at that interface plays a key role in promoting wetting. Formation of CuAlO2 and dissolution of Al2O3 in the melt also influence the contact angle, especially in the range of pO2 > 10−5 bar (1 Pa).