A study of double oxide film defect behaviour in a quiescent aluminium melt

R. Raiszadeh*, W. D. Griffiths

*Corresponding author for this work

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Abstract

    The change in the volume of an air bubble held within commercially pure liquid aluminium was recorded by real time x-ray radiography, to estimate the behaviour of double oxide film defects after entrainment in liquid aluminium. This showed that first oxygen and then nitrogen were consumed by the melt to produce Al 20 3 and AIN respectively. Varying the initial hydrogen contents of the melt also showed that hydrogen could diffuse into the atmosphere within a trapped bubble, and cause it to expand. A mathematical model was developed using the consumption rates obtained from this experiment that included the diffusion of hydrogen, which suggested that the atmosphere within a double oxide film defect should be consumed by the surrounding AI melt in less than two minutes. In addition, a double oxide film-free liquid aluminium melt was poured into ceramic test bar moulds which then held in the liquid state for 20 minutes. Study of the fracture surfaces suggested that the two non-wetting surfaces of a double oxide film defect might bond to each other, after the internal atmosphere of the film was consumed, and that this could occur in 20 minutes or less.

    Original languageEnglish
    Title of host publicationInstitute of Cast Metals Engineers - 67th World Foundry Congress, wfc06: Casting the Future
    Pages864-873
    Number of pages10
    Volume2
    Publication statusPublished - 2006
    Event67th World Foundry Congress: Casting the Future, wfc06 - Harrogate, United Kingdom
    Duration: 5 Jun 20067 Jun 2006

    Conference

    Conference67th World Foundry Congress: Casting the Future, wfc06
    Country/TerritoryUnited Kingdom
    CityHarrogate
    Period5/06/067/06/06

    Keywords

    • Aluminium alloys
    • Hydrogen porosity
    • Oxide films

    ASJC Scopus subject areas

    • Colloid and Surface Chemistry
    • Surfaces and Interfaces

    Fingerprint

    Dive into the research topics of 'A study of double oxide film defect behaviour in a quiescent aluminium melt'. Together they form a unique fingerprint.

    Cite this