The present investigation aims at fabricating a functionally graded Al-6Cr-Y2O3 composite and its microstructural and property characterization. Al-6Cr-alloys with varying percentage of Y2O3 (5-10 vol. %) have been used to fabricate FGM by powder metallurgy route. The samples were subsequently subjected to solution treatment at 610°C for 4 h followed by artificially aged at 310°C for 4 h. The microstructure, hardness and wear behavior of these FGM have been evaluated. FGM exhibited superior hardness (360 ± 5 VHN) as compared to the unprocessed composites (220 ± 5 VHN) due to the uniform dispersion of Y2O3 particles. Wear resistance of Al-6Cr-10 Y2O3 FGM were compared that of with pure Al-6Cr alloy by dry abrasive wear test. Al-6Cr-10 Y2O3 FGM composites were found to exhibit higher wear resistance with the minimum wear rate of 0.009 mm3/m compared to the Al- 6Cr alloy wear rate 0.02 mm3/m.

Friction Stir Process (FSP) was employed to develop Cupro-Nickel/Zirconium Carbide (Cu-Ni/ZrC) surface composites. Five different groove widths ranging from 0 to 1.4 mm were made in CuNi alloy plate to incorporate different ZrC volume fraction (0, 6, 12, 18 and 24 %) to study its influence on the structure and properties of Cu-Ni/ZrC composite. Processing was performed at a Tool Rotational Speed (TRS) of 1300 rpm, Tool Traverse Speed (TTS) of 40 mm/min with a constant axial load of 6 KN. The study is performed to analyse the influence of ZrC particles and the volume fraction of ZrC particles on the microstructural evolution, microhardness, mechanical properties, and tribological characteristics of the Cu-Ni/ZrC composite. The fracture and worn-out surfaces are analysed using Field Emission Scanning Electron Microscope (FESEM) to identify the fracture and wear mechanisms. The results demonstrated a simultaneous increase in microhardness and tensile strength of the developed composite because of grain refinement, uniform dispersion, and excellent bonding of ZrC with the matrix. Besides, the wear resistance increases with increase in volume fraction of ZrC particles in the composite. The surface morphology analysis revealed that the wear mechanism transits from severe wear regime to mild wear regime with increase in volume fraction of ZrC particles.

In the present investigation Ni particles were added in varying weight fractions (0.5, 1.0 and 1.5%) to AA6061 alloy during stir casting. To prepare Al-Ni intermetallic reinforced Aluminium Metal Matrix Composites (Al MMCs), as-cast samples were subjected to T6 treatment (Solutionization at 550°C followed by ageing at 2,4,6,8 and 10 hours). Base alloy was also subjected to T6 treatment for comparison purpose. Hardness of the samples were obtained using Vickers hardness test. Samples in the peak aged (T6) condition were subjected to metallographic examination. Influence of Ni particles on the hardness and grain refinement was investigated. X-ray Diffraction analysis of the Ni added samples revealed the presence of Al-Ni intermetallic phase formation in the peak aged (T6) Condition. Scanning Electron Microscope – Energy Dispersive X-Ray Spectroscopy analysis of composites in the peak aged (T6) condition were carried out to study the formation of the Al-Ni intermetallic phase. Effect of Al-Ni intermetallic phase on wear and friction behavior of the composite samples were studied and compared with that of the base alloy in the peak aged (T6) condition.