Effect of treatment temperature on the texture of mechanically alloyed Fe-40at.%Al+Y2O3 intermetallic’

The texture evolution of a Fe–40 at.% Al alloy reinforced with Y2O3 particles 1 wt.%., produced by extrusion at 1373 K of mechanically alloyed powders, was investigated after thermal treatments up to 1573 K. The orientation distribution function ODF. of the as-extruded material shows a 110: fibre texture with a secondary 320: component. Following heating up to 1373 K, the texture does not change whereas grain re-orientation occurs at 1473 K: the 211: and 023: directions become predominant along the axis of the main and the secondary texture components, respectively. TEM observations after heating proved that dispersoid particles coarsen at temperatures higher than 1373 K and progressively lose their capability of pinning grain boundaries. Following the 1573 K treatment, abnormal grain growth occurs favoured by the presence of a secondary texture component. The results are discussed on the basis of the Humphreys theory