Mechanical characterization of graphene-aluminum nanocomposites

In the current work, Al6061-based composites (2 wt% SiC) and nanocomposites (2 wt% BN, TiO2, Al2O3, MWCNT and Graphene) were prepared via a conventional melt stirring and ultrasonic-assisted melt-stirring approach. In this study, an effort has been made to reduce the agglomeration and clustering of reinforcing particles in the matrix slurry. Hence, reinforcing particles were pre-processed employing ultrasonic liquid processing (ULP) and ball milling (BM) approach prior to mixing in molten matrix slurry. Further, microstructure and mechanical characterization of the specimens fabricated via conventional melt stirring and ultrasonic-assisted melt-stirring approaches were performed and compared. The microscopic analysis (optical microscopy and scanning electron microscopy), microhardness, tensile strength, flexural strength and fractography were performed to analyze the influence of conventional melt-stirring and ultrasonic-assisted melt-stirring on the resulting properties of the fabricated composite and nanocomposite specimens. Microstructure investigations demonstrated better dispersal of reinforcing particles in the specimens prepared via a combined effort of ultrasonic-assisted melt-stirring and reinforcement pre-processing approach. Also, mechanical properties investigation revealed that the specimens prepared via the ultrasonic-assisted melt-stirring approach have superior strength and hardness over the specimens fabricated via the conventional melt-stirring technique. The ultimate tensile and flexural strength of Al6061-2 wt%BN nanocomposite prepared via ultrasonic-assisted melt-stirring reached 246.01 and 498.03, which was 143.57 % and 116.26 % higher than that of Al6061 specimen prepared via conventional melt-stirring. Al6061-2 wt%MWCNT nanocomposite prepared via ultrasonic-assisted melt-stirring has a maximum microhardness (Vickers’s) of 117.1 HV, which was 74.25 % higher than that of Al6061 prepared via conventional melt-stirring. Moreover, Al6061-2 wt%SiC nanocomposite prepared via ultrasonic-assisted melt-stirring has a maximum (Rockwell) of 89.8 HR, which was 105.02 % higher than that of Al6061 prepared via conventional melt-stirring. 

Microstructure and Mechanical Characterization of Al6061 Based Composite and Nanocomposites Prepared via Conventional and Ultrasonic-assisted Melt-stirring Techniques

Mechanical and corrosion properties of Al + 20 vol% (TiC + TiB_2) composites containing different amounts of MWCNTs produced by mechanical alloying and spark plasma sintering processes were investigated. X-ray diffraction analysis was used to identify the formation of the different phases. Field emission scanning electron microscopy equipped with EDS was utilized for microstructural studies. The Young's modulus and hardness of the composites were evaluated by nanoindentation test. The corrosion behavior of samples was investigated by polarization and impedance tests. X-ray diffraction analysis showed that TiC and TiB_2 phases were formed during the mechanical alloying. The results of microstructural studies showed that the reinforcement particles were completely dispersed in the aluminum matrix. Also, it was found that the maximum hardness and the maximum Young's modulus belonged to the composite sample containing 1 wt% of MWCNTs. The highest corrosion resistance was also observed in the sample containing 1 wt% of MWCNTs. Graphical abstract

Characterization of Al/(TiC + TiB_2) hybrid composites containing different amounts of MWCNTs produced by SPS

Friction Stir Processing of Multiwalled Carbon Nanotubes Reinforced Al-Mg-Si Alloy Composites

Influence of Graphene Addition on Microstructure and Mechanical Properties of Homogenized Al4032–Graphene Composites Processed Through ECAP

The present investigation deals with the microstructural and mechanical properties of pure aluminium graphene nano-platelets (GNPs) composites. The contents of GNPs were varied from 0.50 to 2 wt% in pure aluminium matrix. The composites fabrication was done through stir casting technique, and the investigations revealed that pure Al–0.5% GNPs composite displayed better mechanical properties in comparison with pure Al–1% GNPs, 1.5% GNPs and 2% GNPs composites for tensile strength and hardness test. The SEM, fractographic analysis, XRD and TEM analyses were examined to investigate the surface morphology, and phase analysis confirms that there is a uniform distribution of GNPs in the base matrix (pure Al) and results in low porosity. This leads to a considerable improvement in the mechanical properties of pure Al–0.5% GNPs compared to other weight percentages due to high surface area and curled nature of graphene and makes it potential for diverse applications.

Venkata Subbaiah

Papers

Microstructural Analysis and Mechanical Properties of Pure Al–GNPs Composites by Stir Casting Method