The stability of the oxide dispersion in INCONEL alloy MA6000

Abstract

Analytical transmission electron microscopy has been used to examine the stability of the oxide dispersion in the mechanically alloyed, nickel-based, dispersion strengthened superalloy, INCONEL alloy MA6000. Hot rolling consolidated powder does not cause any change to the dispersoid but zone annealing, however, induces a number of changes to the four mixed Y-A1 oxide phases which constitute the dispersoid: the yttrium aluminium monoclinic (Y4Al2O9) phase disappears; the yttrium aluminium garnet (Y3Al5O12) and yttrium aluminium perovskite (YAlO3) phases rotate in the host crystals and orientation relationships arise between these oxides and the matrix and the yttrium aluminium hexagonal (YAlO..