Oxide dispersion strengthened (ODS) alloys are produced by the mechanical alloying of powders. The powder constituents can be in the elemental, intermetallic or pre-alloyed state.
The metal and oxide (i.e. Yttria) powders are blended and mechanically alloyed using a ball mill. The repeated impacts of this process cause smearing together of the powders followed by shearing which generates particles that each contain a fine mixture of the constituents.
The powder is then packaged into sealed containers that are hot worked into simple primary shapes, either by extrusion or hot isostatic pressing (HIP). The resultant product is dense and fine grained (less than 11µm) but has highly developed, directional residual strain. The alloys are then re-crystallised at about 1280-1350°C when large and highly elongated grains form, as shown in the figure below.