Microstructure and properties of NiAl/TiC composite synthesized by spark plasma sintering of mechanically activated elemental powders

In this study, NiAl/TiC0.95 composite was synthesized by reactive spark plasma sintering of mechanically activated elemental powders. The microstructure and properties of activated powders and sintered samples were evaluated. The elemental powders were milled after different milling times and as-mixed and 10 h milled powder mixtures were sintered by the reactive spark plasma sintering method. The phase and the microstructure changes were evaluated by x-ray diffraction and scanning electron microscopy/energy dispersive spectroscopy, respectively. The XRD pattern of 0 h milled powder after sintering showed that Ni3Al, Ni2Al3 beside NiAl and TiC0.75 formed. While after the sintering of 10 h mechanically activated powder, the Ni3Al and Ni2Al3 were eliminated and NiAl remained with TiC0.95. The nanoindentation result of the SPSed sample showed a hardness of 12.2 ± 0.1 GPa with an elastic modulus of 25.0 ± 0.5 GPa.