Atomic level characterization of defects in microalloyed NiAl: An atom probe investigation

摘要

Since mechanical behavior is largely controlled by the microstructure (particularly dislocations, substitutional solutes, and solute segregation to grain boundaries) atom probe field ion microscopy is well suited to studying such microstructural features. The atom probe has been used to explain changes in yield stress when NiAl is doped with B, C, Be, or Zr/Mo. It showed that the beneficial effect of B segregation is masked by formation of ultrafine, deleterious second-phase particles. Be occupied Al sites almost exclusively. Zr segregated to both grain boundaries and dislocations.