Dispersion strengthened intermetallics by mechanical alloying : creep results and dislocation mechanisms

Abstract

In order to increase the creep strength, small dispersoids were introduced into the intermetallic compound NiAl by mechanical alloying. Under favorable conditions, the resulting specific creep rates approach those of superalloys. To accompany these experimental effects, a new model has been developed which predicts tendencies for the success of dispersion strengthening in ordered alloys. It is shown that the dissociation distance of the partial dislocations, relative to the dispersoid particle size, has an important effect on the strengthening achievable.