
 Copper (Cu) composites hybridized with nano-sized reinforcing material are gathering attraction in such fields as automobile, aerospace, and power transmission due to their higher strength. Unlike conventional reinforcing materials, extraordinary mechanical properties and high electrical and thermal conductivity make nanomaterials highly useful reinforcement materials to improve the properties of pristine metals. Over the last two decades, several studies have been conducted to determine the effect of distinctive 2D nanomaterials, such as silicon carbide, aluminium oxide, copper nanotube, and graphene as reinforcement on properties of metal matrices. This study comprehensively reviews the effect of hybrid reinforcements on the mechanical properties of Cu composites having graphene as one of the reinforcements. Also, the contribution of these reinforced nanomaterials composition and their dispersion in the pure Cu matrices have also been explained in detail. In comparison with Cu composites fabricated with a single 2D reinforcement material, composites incorporating hybrid nano reinforcement, exhibit better mechanical behaviour. Additionally, the improvement in mechanical strength would enhance their capability to withstand altering thermal and surrounding environmental conditions.

Effect of Hybrid Reinforcements on the Mechanical Properties of Copper Nanocomposites

In this research, graphene/Al6061 aluminum matrix nanocomposites were fabricated by stir casting, and the influence of graphene nanoplates on microstructure and mechanical properties of the 6061 aluminum alloy were investigated by field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy, tensile and hardness testing analysis methods. The major limitation in the utilization of 6061 aluminum alloy in heavy stress applications such as airplane fuselages, wings, internal panels, and luxury vehicles chassis is low strength and hardness. This deficiency of 6061 aluminum alloy was tackled by successful reinforcement of graphene nanoplates in 2, 4, 6, 8 and 10 wt.%, using the stir casting process. The FESEM micrographs showed that the graphene nanoplates were uniformly distributed in the 6061-aluminum matrix alloy and tensile strength, hardness, and yield strength enhanced remarkably as compared with unreinforced 6061 aluminum alloy. The as-cast tensile strength, hardness, and yield strength of the graphene/Al6061 nanocomposites were improved by 127%, 158%, and 402%, respectively, compared with the unreinforced Al6061 alloy. It is concluded that the nano thickness of graphene, reinforcement quantity, and manufacturing process are the major factors for the enhancement of microstructure and mechanical properties of graphene/Al6061 nanocomposites.

Enhanced microstructure and mechanical properties of Al6061 alloy via graphene nanoplates reinforcement fabricated by stir casting

Aluminium LM13 alloy based hybrid particulate composites have been processed by adding boron carbide (B4C) and titanium diboride (TiB2) particles. The wt% of titanium diboride (TiB2) is varied as 0, 3, 6, 9, 12, 15 and a constant 3 wt% of boron carbide is used to prepare the composites. Stir cast route is used to fabricate the composites. The microstructures of castings are examined using computer aided image analyzer. Vicker hardness, yield strength, ultimate tensile strength and energy absorbed by the composites are examined and reported. The results show that uniform dispersion of TiB2 and B4C reinforcement phases in Al LM13 alloy. Micro hardness of composites enhanced upto 36.6% when compared to Al alloy reinforced with 3 wt% of B4C particles. Ultimate tensile strength of Al alloy is improved from 151 MPa to 192 MPa by reinforcing 15 wt% of titanium diboride particles. LM13 aluminium alloy hybrid particulate composites offers superior vicker hardness, yield strength, utlimate tensile strength and impact strength over LM13 aluminium alloy based single particle reinforced composites.

Assessment of mechanical properties of LM13 aluminum alloy hybrid metal matrix composites

Metal matrix nanocomposites: future scope in the fabrication and machining techniques

Microstructural Characterization, Mechanical and Taguchi Wear Behavior of Micro-Titanium Carbide Particle-Reinforced Al2014 Alloy Composites Synthesized by Advanced Two-Stage Casting Method

MMC based on aluminium (Al) were produced for light-weight applications especially in aviation and automobile areas. Present paper deals with the fabrication and mechanical performance of AA6061 matrix composites fortified with Al2O3 (alumina) and graphene particulates. Fluid metallurgy method namely stir casting route was employed for fabricating the hybrid composites. Al2O3p and graphene powder are mixed in different weight fractions in which graphene (1 wt. %) particle reinforcement is held consistent and Al2O3 reinforcement is differed freely with 5, 10 and 15 wt. %. Using optical analyser and SEM equipment, microstructural examination is carried out and the result reveals that the graphene and Al2O3 particles prevalently are homogeneously appropriated on the grain limits of Al matrix and Al2O3 particles are disseminated between graphene in the as-cast AA6061 MMC’s. Detailed analysis on investigation of the microstructure and mechanical aspects of Al6061-graphene-Al2O3p composites is presented by following ASTM guidelines; results uncovered that with increment in reinforcement particles, there is an enhancement in the hardness, ultimate strength, yield strength and a decline in the elongation values was however noticed when contrasted with Al6061 alloy. Fractography investigation revealed dimples in unreinforced alloy and the composite.

Development and Mechanical Characterisation of Al6061-Al2O3-Graphene Hybrid Metal Matrix Composites

An Al2014–alumina (Al2O3) composite’s characteristics are significantly influenced by the reinforcement particle size variation. Therefore, this study examines the microstructure, mechanical, fractography, and wear performance of an Al2014–Al2O3p composite made using a unique two-stage stir casting method and various alumina weight fractions (9, 12, and 15 wt %). Three categories of alumina particle size are used, i.e., fine particle size (FPS, 8 μm), intermediate particle size (IPS, 53 μm), and coarse particle size (CPS, 88 μm). The shapes of the composites were characterized using scanning electron microscopy. According to scanning electron microscopic analyses of the microstructure, the FPS dispersion was more uniform than IPS and CPS, whereas CPS causes agglomeration. Additionally, the studies show that the FPS composite outperformed CPS and IPS composites in terms of mechanical characteristics and wear performance. The fractography study shows conical and equiaxed dimple failure in the Al2014 matrix and the circular cavities.

Bharath Vedashantha Murthy

Papers

Development and Mechanical Characterisation of Al6061-Al2O3-Graphene Hybrid Metal Matrix Composites

Al2014–Alumina Aerospace Composites: Particle Size Impacts on Microstructure, Mechanical, Fractography, and Wear Characteristics

Impact of Bonding Temperature on Microstructure, Mechanical, and Fracture Behaviors of TLP Bonded Joints of Al2219 with a Cu Interlayer