High temperature structural coarsening of an ODS FeAl intermetallic

The coarsening of oxide particles and grains in an ODS FeAl intermetallic has been examined during annealing at high temperatures under conditions where recrystallization does not yet occur. Coarsening of the yttria particles is shown to be controlled by the diffusion of the metallic species through the intermetallic matrix, while the increases of grain size by grain growth are determined by the pinning action of the large number of yttria particles. Hardness falls during the annealing and is seen to depend on both particle size increases and grain size increases.