Nucleation of gaseous hydrogen bubbles is the initial stage of the directional solidifying process for production of porous copper or copper alloys. The present work investigates the nucleation mechanism of these bubbles in Cu and its alloys. Cracks and cavities in oxide particles greatly facilitate bubble nucleation by acting as heterogeneous nucleation sites. Theoretical studies of the effect of melt comparison on the interfacial energetics at the oxide-melt interface show that additions of Sn to a Cu melt favors the nucleation process, whereas additions of Al retard it. Thermodynamic limits set by hydrogen solubility and its dependence on temperature, pressure, and alloy composition have been evaluated.
|Number of pages
|Journal of Materials Synthesis and Processing
|Published - Jul 1995
ASJC Scopus subject areas
- General Materials Science