Fabrication and mechanical properties of microalloyed and ceramic particulate reinforced NiAl-based alloys

NiAl-based alloys and their composites reinforced with in situ formed TiC and externally added ceramic particles are fabricated by hot-pressing. Their microstructures and mechanical properties are evaluated. Comparatively, the Ti- and/or C-alloyed NiAl and the ceramic particulate reinforced composites possess a significant improvement in both flexural strength fracture toughness at room temperature. Nevertheless, the NiAl–TiC-nano-Al2O3 composite has low strength, mainly due to the existence of residual porosity, inhomogeneous distribution and severe agglomeration of nano-scaled Al2O3 particle within the NiAl matrix.