Effect of treatment temperature on the texture of mechanically alloyed Fe-40 at./100 al＋Y_2O_3 intermetallic

摘要

The texture evolution of Fe-40 at./100 Al alloy reinforced with Y_2O_3 particles (1 wt./100), 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.