Microstructural and mechanical characterisation of ODS ferritic alloys produced by mechanical alloying and spark plasma sintering

Powders with basic composition Fe-14Cr-2W-0.4Ti were mechanically alloyed (MA) with Y2O3 in a planetary ball mill under two different rotation speeds. Consolidation of the as-milled powders was performed by spark plasma sintering (SPS). As-milled powders showed a highly deformed microstructure with elongated nanometric grains, around 50nm and different nanoclusters were found depending upon the rotational speed that produces different stages on the nanoclusters evolution. In the case of SPS materials, grain growth occurred during the SPS process and it was possible to observe the influence of the MA parameters, with larger and more homogeneously distributed grains at the higher speed. The mechanical behavior of the SPS compacts was evaluated by tensile and small punch testing also showing the influence of the MA parameters in the material behavior.