OxideDispersionGehärtete

Oxide dispersion hardened (ODS) alloys are a class of metallic materials that derive their enhanced high-temperature strength from the presence of finely dispersed, thermodynamically stable oxide particles within a metallic matrix. These oxide particles, often yttrium oxide (Y₂O₃) or other rare earth oxides, act as obstacles to dislocation movement, thereby significantly increasing the alloy's creep resistance and tensile strength at elevated temperatures.

The production of ODS alloys typically involves mechanical alloying or powder metallurgy techniques. In mechanical alloying, elemental or pre-alloyed powders are subjected to high-energy ball milling, which simultaneously alloys the constituent metals and disperses the oxide particles. The resulting powder is then consolidated, often by hot isostatic pressing or extrusion, to form a dense, solid material. Alternative methods include inert gas atomization followed by consolidation or specialized casting techniques.

ODS alloys find application in environments where extreme temperature and stress conditions are encountered. These include components for gas turbines, such as turbine blades and vanes, as well as nuclear reactor fuel cladding and structural components. Their resistance to oxidation and corrosion at high temperatures also makes them suitable for various aerospace and industrial applications. The stability of the oxide dispersion ensures that the strengthening effect is maintained over long periods of service at elevated temperatures, distinguishing them from alloys strengthened by precipitation hardening, which can suffer from particle coarsening.