Effect of holding time before solidification on double-oxide film defects and mechanical properties of aluminium alloys

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

Authors

External organisations

  • Arab Academy for Science & Technology and Maritime Transport
  • American University in Cairo

Abstract

Double oxide films (bifilms) have been held responsible for the variability in mechanical properties of aluminium castings. It has been suggested that the air entrapped inside a bifilm can react with the surrounding melt leading to its consumption, which might improve the mechanical properties of the castings. In this work, the effect of the holding time of the melt before solidification on the distribution of mechanical properties, and by implication, on entrained double oxide films, was investigated for different aluminium alloys. The Weibull moduli of the plate castings were determined under tensile conditions, and their fracture surfaces examined for evidence of oxide films. The results suggested the occurrence of two competing mechanisms during the holding treatment. The consumption of air inside the bifilms due to reaction with the surrounding molten metal may lead to improvements in mechanical properties, but this may be accompanied by hydrogen passing into the bifilms, which has a deleterious effect on properties.

Details

Original languageEnglish
Title of host publicationTMS Annual Meeting
Publication statusPublished - 2011
EventShape Casting: 4th International Symposium 2011 in Honor of Prof. John T. Berry - Held During the TMS 2011 Annual Meeting and Exhibition - San Diego, CA, United States
Duration: 27 Feb 20113 Mar 2011

Conference

ConferenceShape Casting: 4th International Symposium 2011 in Honor of Prof. John T. Berry - Held During the TMS 2011 Annual Meeting and Exhibition
CountryUnited States
CitySan Diego, CA
Period27/02/113/03/11

Keywords

  • Aluminium, Casting, Double oxide film defects, Mechanical properties