Abstract
This article reports results from an experiment where a bubble of air was held at a constant temperature in a liquid Al melt, with the volume of the bubble monitored continuously using real-time X-ray equipment. When the H content of the surrounding melt was low, the volume of the trapped air bubble reduced with time, as the O and N in the bubble atmosphere reacted with the Al to form Al2O3 and AlN. When the H content of the melt was increased to about 0.3 ml 100 g(-1) Al, the H in solution passed into the air bubble causing its expansion. In an Al casting the same effect would cause an entrained double oxide film defect to act as a site for the growth of H-driven gas porosity. The way in which the oxide film defects might behave in forming H porosity has been discussed.
Original language | English |
---|---|
Pages (from-to) | 3402-3407 |
Number of pages | 6 |
Journal | Journal of Materials Science |
Volume | 44 |
Issue number | 13 |
DOIs | |
Publication status | Published - 1 Jul 2009 |
Keywords
- PEPT
- shape casting
- Positron Emission Particle Tracking
- radioactivity
- Inclusions