Development and Characterization of ZrO2-Graphene Oxide Reinforced Al6061 Composite using Powder Metallurgy

Abstract

The Automotive and Aerospace industry is revolutionizing driven by advancement in material. Aluminum and its alloys are of prime importance for weight reduction, but the growing demand of industry needs more advanced materials to enhance the mechanical and tribological properties. Aluminum is reinforced with different particles or fibers. Graphene or graphene derivatives are one of the hardest and highest strength materials. Graphene reinforced aluminum metal matrix composites (GRAMMCs) are of great interest due to their intrinsic properties such as high specific strength, high specific stiffness, low density, good oxidation resistance and enhanced tribological performance and are used in aerospace and automobile industry. Graphene oxide with its exceptional strength material could be a promising reinforcement in aluminum metal matrix composites to boost their mechanical properties. This study was conducted to develop graphene oxide and zirconia reinforced hybrid Al6061 metal matrix nanocomposites by using liquid phase sintering in an inert atmosphere. Graphene oxide concentration was varied at 0.2 wt.%, 0.4 wt.%, 0.6 wt.% and 1.0 wt.% while zirconia concentration was maintained constant at 2 wt.% ZrO2. All the composite samples were sintered at 500°C and 550°C with dwell times of 60 min, 120 min and 180 min. Optical microscopy and scanning electron microscopy was employed to study the microstructure while compression test was performed to evaluate the compressive strength of composites. The relative sintered density was measured by Archimedean principle and is found maximum for the sample 0.2wt.%GO/2wt.%ZrO2/Al6061.There is 23% improvement in microhardness and 16% improvement in compressive strength by adding 0.6wt.% graphene oxide in the sample 0.6wt.%GO/2wt.%ZrO2/Al6061 sintered at 550°C for 180min and is found maximum among all composites.