Mechanical alloying of IN-738

Experiments and simulations of directionally annealed ODS MA 754

“…Measurements of grain aspect ratio (grain length to grain width) performed after directional annealing showed that the largest grain aspect ratio (11) was obtained for the lowest hot-zone velocity (2 mm/h), see Table 2, in a good agreement with previous studies on ODS superalloys [7]. The decreasing grain aspect ratio with increasing hot-zone velocity is attributed to the fact that the grain growth front cannot keep up with the moving hot-zone at higher hot-zone velocities.…”

“…However, at the levels present (say, radius, 10 nm; volume fraction, 0.025), did not prevent abnormal grain growth [10]. The largest grain aspect ratios were obtained at the slowest rates of hot-zone movement [8,11]. For example, for MA 760, the grain aspect ratio increased (from ∼10:1 to grains encompassing the entire specimen length) as the zone-annealing speed decreased (from 60 to 4.2 cm/h) [12].…”

“…Directional primary recrystallization appears to have been used to produce large, [1 1 0]-oriented columnar-grained specimens of some ODS superalloys [8][9][10][11][12]. The critical parameters in the processing were the deformation prior to recrystallization and the recrystallization temperature.…”

Recrystallization of Dispersion-Strengthened Copper Alloys

“…Long term annealing of boron-added alumina DS copper alloys results in an unexpected transformation from fine -Al 2 O 3 to coarse 9Al 2 O 3 -2B 2 O 3 with a concurrent recrystallization of the matrix to form a large and elongated grain structure (Kim & Lee, 2002). Whereas Ni-based DS alloys are used in a coarse-grained condition to increase high-temperature creep resistance (Gessinger, 1976;Stephens & Nix, 1985), key applications of alumina DS copper alloys require them to be in a fully workhardened state. Consequently, a large decrease in room temperature strength due to recrystallization is not desirable.…”

Annealing behavior of alumina dispersion-strengthened copper strips rolled under different conditions

“…[8] Unlike Ni-based oxide dispersionand more importantly, it retains these properties at elevated strengthened alloys used for high-temperature creep resistant temperatures. [1] These unique characteristics are mainly applications in a coarse-grained condition, [11,12] the major attributed to the presence of uniformly dispersed fine application of ADSC is confined to the use in a fully cold-␥ -Al 2 O 3 particles, which are thermally stable oxide forms. worked condition.…”