Mechanical Properties of Mechanical Alloyed and Spark Plasma Sintered NiAl-Based Intermetallic Composites

The mechanical and microstructural properties of NiAl-based intermetallic composites reinforced with graphene nanoplates (GNPs) were investigated. Three different graphene contents, 0.5, 1 and 1.5 wt.%, were considered to investigate its effect on the nanocomposite properties produced by mechanical alloying and spark plasma sintering. The results showed that in the presence of graphene, the bending strength improved by almost 52.7% compared to the pure NiAl due to homogenous distribution of GNPs, the grain refinement and strength of the graphene. Among all the produced samples, NiAl-1 wt.% GNPs exhibit the highest mechanical and microstructural properties such as toughness (6.21 GPa√m), microhardness (6.71 GPa) and bending strength (83.88 ± 4 MPa). The perovskite phase (Ni 3 AlC 0.5 ) was formed by increasing the graphene up to 1.5 wt.%, which reduced the mechanical properties compared to the other samples.