Size effect of functionalized reinforcements on the microstructure and mechanical properties of flaky Al-CNT composites

This paper reports the scientific aspects of the process parameters that result in the production of flaky Aluminium (Al) powder as the matrix with 2% volume fraction of Multi Walled Carbon Nanotubes (MW-CNTs) having the diameter of 8, 20 and 50 nm uniformly dispersed by magnetic stirring. Initially the Al powder is ball milled for 6 h to get flaky Al. Then it was coated with PVA for better adsorption with CNTs. The fabricated Al/CNT composite powders with different sizes of CNT diameter were consolidated by Spark plasma sintering (SPS). The reaction between Al and CNTs results in the formation of Al4C3 precipitates. Sintered composites were tested for hardness, toughness and tribological wear. The maximum values of hardness (69 3 Hv) and toughness (1.43 MPa.m1/2) are obtained when the size of the reinforcement is 50 nm. The microstructural observations also reveal the same. From the study, it is concluded that the size of the reinforcement plays a major role in enhancing the mechanical properties of the composite.