Browsing by Author "StJohn, David H."

Now showing items 1-5 of 6

  • Effect of iron on grain refinement of high-purity Mg–Al alloys

    Cao, Peng; Qian, Ma; StJohn, David H. (Elsevier Ltd, 2004-07)
    The effect of iron on the grain refinement of high-purity Mg–3%Al and Mg–9%Al alloys has been investigated using anhydrous FeCl3 as an iron additive at 750 °C in carbon-free aluminium titanite crucibles. It was shown that ...

  • Effect of manganese on grain refinement of Mg–Al based alloys

    Cao, Peng; Qian, Ma; StJohn, David H. (Elsevier, 2006-06)
    Manganese is a grain refiner for high purity Mg–3%Al, Mg–6%Al, Mg–9%Al, and commercial AZ31 (Mg–3%Al–1%Zn) alloys when introduced in the form of an Al–60%Mn master alloy splatter but the use of pure Mn flakes and ALTAB™ ...

  • Grain coarsening of magnesium alloys by beryllium

    Cao, Peng; Qian, Ma; StJohn, David H. (Elsevier Ltd, 2004-10)
    A trace of beryllium can lead to dramatic grain coarsening in Mg–Al alloys at normal cooling rates. It is, however, unclear whether this effect applies to aluminium-free magnesium alloys or not. This work shows that a trace ...

  • Mechanism for grain refinement of magnesium alloys by superheating

    Cao, Peng; Qian, Ma; StJohn, David H. (Elsevier, 2007-04)
    The mechanisms for grain refinement of magnesium alloys by superheating have remained ambiguous since 1931. A model has been proposed on the basis of the recent understanding of the grain refinement of both high purity and ...

  • Native grain refinement of magnesium alloys

    Cao, Peng; Qian, Ma; StJohn, David H. (Elsevier Ltd, 2005-10)
    High purity Mg–Al type alloys have a naturally fine grain size compared to commercial purity alloys with the same basic composition. This is referred to as native grain refinement. It is shown that native grain refinement ...