Oxide dispersion-strengthened alloy

This mismatch in interfaces results in a high interfacial energy, which impedes dislocation.

Dislocation climb is a diffusional process, which is less energetically favourable, and mostly occurs at higher temperatures that provide enough energy to advance via the addition and removal of atoms.

[6] Because the particles are incoherent, glide mechanisms alone are not enough and the more energetically exhausting climb process is dominant, meaning that dislocations are stopped more effectively.

[8] Dislocations are not limited to either all local or all general climb as the path that requires less energy is taken.

[12] This detachment phenomenon is a result of the interaction between the particle and the dislocation where total elastic strain energy is reduced.

[14] The following equations represent the strain rate and stress as a result of oxide introduction.

Hoelzer and coworkers showed that an alloy containing a homogeneous dispersion of 1-5 nm Y2Ti2O7 nanoclusters has superior creep properties to an alloy with a heterogeneous dispersion of 5-20 nm nanoclusters of the same composition.

[15] ODS steels are commonly produced through ball-milling an oxide of interest (e.g. Y2O3, Al2O3) with pre-alloyed metal powders followed by compression and sintering.

It is believed that the oxides enter into solid solution with the metal during ball-milling and subsequently precipitate during the thermal treatment.

This process seems simple but many parameters need to be carefully controlled to produce a successful alloy.

Leseigneur and coworkers carefully controlled some of these parameters and achieved more consistent and better microstructures.

The powder is annealed at higher temperatures to begin a controlled nucleation of the oxide clusters.

NASA used ResonantAcoustic mixing and additive manufacturing to synthesize an alloy they termed GRX-810, which survived temperatures over 1,090 °C (1,990 °F).