Enhancing the Strengthening Effect of Graphene-Nanoplates in Al Matrix Composites by Heterogeneous Matrix Design

Abstract

In the present work, the properties of graphene-nanoplates/aluminum (GNPs/Al) composites with a heterogeneous matrix design were investigated. The advantage of the heterogeneous matrix was investigated by the finite element method. Then, 0.6 wt.% (GNPs/6061Al)/2024Al (heterogeneous matrix) and 0.6 wt.% GNPs/6061Al composites were prepared by ball milling, pressure infiltration technology, and hot extrusion. The aggregation of GNPs was eliminated and the interlayer slide of GNPs was observed. Mechanical property test results show that the mechanical properties of the heterogeneous matrix composite are better than that of a homogeneous matrix composite, including strength, elastic modulus, and plasticity. It is assumed that the heterogeneous matrix design enhances the non-uniform stress field during the deformation treatment. This improves the dispersion of GNPs, grain refinement, and produces the few-layer graphene (FLG), thus enhancing the strengthening effect of GNPs. Meanwhile, heterogeneous matrix design is thought to introduce more hardening mechanisms to increase the plasticity of materials and improve the intrinsic trade-off of strength and toughness.

Mechanical Behaviour and Morphology of Thixoformed Aluminium Alloy Reinforced by Graphene

“…However, no peaks of GNPs are observed because of the low graphene content and the limited resolution of elements of X-ray diffraction. Research studies by Shao et al [ 29 ] and Lou et al [ 30 ] have also reported these findings on the absence of GNPs. In addition, there was no obvious peak of the aluminium carbide (Al 4 C 3 ) phase found, thus proving that there was no chemical interaction between GNPs and Al alloy.…”

“…On the other hand, Figure 7 d,f indicate a high accumulation of carbon (C) in the red strip-like phase as GNPs. Agglomeration of GNPs at several locations is observed for 0.5 wt.% and 1.0 wt.% of GNPs/Al composites as a result of a high percentage of GNPs, where the liquid metal has segregated the graphene particles and impeded them from mixing with the aluminium matrix [ 24 , 29 ].…”

Recent trends in two-dimensional graphene derivatives-based composites: Review on synthesis, properties and applications

“…Solid-phase mixing is usually carried out through the powder processing method that is usually proceeded via ball milling or shear mixing. 147,148 Before solution mixing, surface modification of the inorganic material NPs and/or GD sheets is often carried out, so that they can bind through either the covalent interactions (chemical bonding) or the non-covalent interactions (van der Waals forces, hydrogen bonding, π-π stacking, or electrostatic interactions). 20,146 As an example of inorganic NPs/GD covalent interactions, Liu et al 149 demonstrated efficient immunosensor for detection of cardiac marker troponin-I, based on GO/Au NPs nanocomposite that was prepared by solution mixing.…”

“…The primary fabrication processes, also called densification techniques, of the inorganic material NPs/2D GDs composites include, hot extrusion, hot pressing, cold pressing and sinter molding. 19,147,148 Up to date, various sinter molding methods have been employed, including pressureless sintering, field-assisted sintering, high-frequency induction heated sintering, microwave sintering, spark plasma sintering and flash sintering. 148 Recent distinctive characteristic properties 2D Graphene derivatives/metals composites.…”

“…Shao et al revealed that GNPs/Al composite with 0.6 wt% of GNPs, prepared by ball milling followed by hot extrusion, showed 92% improvement in tensile strength over that of pure Al. 147 Also, graphene is able to enhance the thermal conductivity of metallic materials, due to its exceptional thermal conductivity. Yin et al has prepared layered RGO/Cu composite by electrodeposition method, with superior thermal conductivity that is 150% higher than that of pure Cu.…”