ROOM-TEMPERATURE TENSILE DUCTILITY IN POLYCRYSTALLINE B2 NIAL

This study has shown that it is possible to obtain significant tensile ductility in nominally stoichiometric polycrystalline B2 NiAl at room temperature as well as at 473 K. This result is obtained from material which contains low levels of C and O and which has been cast and extruded at low temperature. The brittle failures are predominantly intergranular in nature, whereas increases in the ductility seem to be associated with increasing amounts of transgranular failure. The failures at 873 K exhibit typical ductile fracture features. A comparison of the results presented here with the results obtained more than twenty years ago by Rozner and Wasilewski shows very close agreement for the stoichiometric alloy as well as for the alloys with deviations from stoichiometry.