Investigation on Mechanical and Machinability Properties of Aluminium Metal Matrix Composite Reinforced with Titanium Oxide (TiO2) and Graphite (Gr) Particles

Abstract

This research paper deals with the preparation process and testing of metal matrix composites comprising Aluminium alloy (Al 6061) as the base metal and Titanium oxide (TiO2) and Graphite (Gr) as reinforcements. Due to their high specific strength, superior malleability, lightweight, stiffness and excellent resistance to corrosion, oxidation and wear, the aluminium metal matrix composites are preferred in the automobile and industrial sectors for component manufacturing. No work reported on machinability properties of Titanium oxide (TiO2) and Graphite (Gr) reinforced aluminium composites so far. This study prepared and studied samples composed of variable proportions of titanium oxide and graphite. The samples were prepared using the stir casting method. While stirring, the required additives were added to the molten aluminium mixture. To perform the tests, the samples were prepared according to standard dimensions after solidification. The mechanical properties of the prepared composite were examined using various test procedures, such as strength and hardness. Scanning electron microscopy was used to examine the microstructure of the test composite samples. The EDAX test confirmed the presence of graphite and Titanium oxide in the aluminium based composite specimens. Furthermore, machining was done to study the cutting forces on the tool. The test results showed a significant impact of the reinforced materials on the mechanical and machinability properties of aluminium metal matrix composites. Gr decreases hardness, while TiO2 increases it. TiO2 and Gr reinforcements increase the tensile strength of Al 6061 composites. The addition of TiO2 decreased the composite's elongation. The proof strength of 2 % Al6061 was high, however it decreased with 3 % Gr and increased with TiO2 reinforcement. Reinforcements increase cutting forces during machining; when comparing the machining of Al 6061 to that of 3 % Gr and 5 % TiO2, a 50 % increase in cutting forces is noticed. However, excessive reinforcements may reduce cutting forces due to poor matrix-reinforcement adhesion.