Control of soundness and mechanical properties in aluminium-silicon-magnesium alloys

  • D.S. Edwards

    Student thesis: Doctoral ThesisDoctor of Philosophy


    Previously, specifications for mechanical properties of casting alloys were based
    on separately cast test bars. This practice provided consistently reproducible
    results; thus, any change in conditions was reflected in changes in the mechanical
    properties of the test coupons. These test specimens, however, did not necessarily reflect the actual mechanical properties of the castings they were supposed to represent'. Factors such as section thickness and casting configuration affect the solidification rate and soundness of the casting thereby raising or lowering its mechanical properties in comparison with separately cast test specimens.
    In the work now reported, casting shapes were developed to investigate the
    variations of section thickness, chemical analysis and heat treatment on the
    mechanical properties of a high strength Aluminium alloy under varying chilling
    conditions. In addition, an insight was sought into the behaviour of chills under
    more practical conditions. Finally, it was demonstrated that additional information
    could be derived from the radiographs which form an essential part of the quality
    control of premium quality castings.
    As a result of the work, it is now possible to select analysis and chilling
    conditions to optimize the as cast and the heat treated mechanical properties of
    Aluminum 7% Silicon 0.3% Magnesium alloy.
    Date of AwardJun 1973
    Original languageEnglish
    SupervisorJ.C. Wright (Supervisor) & J.T. Barnby (Supervisor)


    • control
    • soundness
    • mechanical properties
    • aluminium-silicon-magnesium alloys

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