MICROSTRUCTURE AND MECHANICAL-PROPERTIES OF MULTIPHASE NIAL-BASED ALLOYS

The effect of the y’ phase on the deformation behavior fracture resistance of melt-spun ribbons and consolidated bulk specimens of a series of NiAl-based alloys with Co and Hf additions has been examined. The morphology, location, and volume fraction of the y’ phase are significant factors in enhancing the fracture resistance of the normally brittle NiAl-based alloys. In particular, the results indicate that a continuous grain boundary film of y’ can impart limited room temperature ductility regardless of whether B2 or Ll0 NiAl is present. Guidelines for microstructure control in multi-phase NiAl-based alloys are also presented. © 1990, Materials Research Society. All rights reserved.