Alloy Development of Oxide Dispersion Strengthened High Volume Gamma' Nickel-Base Superalloys Made by Mechanical Alloying.

The object of this work was to develop ODS alloys which would derive a significant high temperature strength increment from the retention of high volume fractions 50 of gamma at 2000 F 1093 C. Alloy structure and property investigations were conducted to determine the effects of W, Mo, Ta and Nb combinations substituted on an atomic weight basis into each of three Ni-Cr-Al ternary systems. Specifically, CrAl levels of 1516, 12.517.5 and 1017.5 at . were chosen. Based on promising directional recrystallized structures and mechanical properties, three alloys were selected from the series of 12 compositions, for further development including the effects of BZr alloy modifications, extrusion, hot rolling and heat treatment studies on the directional recrystallization response, structure and mechanical properties. The work confirmed that the high volume fraction of gamma characteristic of these alloys, is an effective means of improving the intermediate temperature strength of ODS superalloys.