Evolution and extensive research on nano technology has yielded several positive facets in the surface engineering which alters the mechanical properties and metallurgical behaviour of substrates as desired by designs specified for critical applications. In this work, plasma spray coating on mild steel using the nanocomposite material of Al2O3 with 13%TiO2 & 1%CNT is carried out to examine the mechanical and metallographic behaviours. The Nano composite material is coated on AISI 1020 substrate using a plasma spray technique. ASTM C-633 standards are followed while performing destructive testing to examine the strength of the bonding. The Nano-structured coat layer exhibit greater resistance to crack growth, higher bonding strength and hardness. The higher strength and toughness obtained is attributed to the formation of net structures. Further, the samples are investigated by using Xray diffraction technique and microscopic techniques. Al2O3 phase shows dominance. Metallographic studies revealed that coating on the substrate illustrates various regions, including the ceramic layer (Al2O3 or Al2O3-13 weight% TiO2) and the matrix, that show little variance due to the coating. Negligible or insignificant amount of spalling or delamination is observed in the coatings. Nevertheless, there is negligible number of visible pinholes in the coatings. Response surface methodology is employed to examine the performance measures and parametric dependencies.