Enhanced tensile properties of aluminium matrix composites reinforced with graphene encapsulated SiC nanoparticles

Abstract

Due to a high propensity of nano-particles to agglomerate, making aluminium matrix composites with a uniform dispersion of the nano-particles using liquid routes is an exceptionally difficult task. In this study, an innovative approach was utilised to prevent agglomeration of nano-particle by encapsulating SiC nanoparticles using graphene sheets during ball milling. Subsequently, the milled mixture was incorporated into A356 molten alloy using non-contact ultrasonic vibration method. Two different shapes for graphene sheets were characterised using HRTEM, including onion-like shells encapsulating SiC particles and disk-shaped graphene nanosheets. This resulted in 45% and 84% improvement in yield strength and tensile ductility, respectively. The former was ascribed to the Orowan strengthening mechanism, while the latter is due primarily to the fiber pull-out mechanism, brought about by the alteration of the solidification mechanism from particle pushing to particle engulfment during solidification as a consequence of high thermal conductive graphene sheets encapsulating SiC particles. Due to a high propensity of nano-particles to agglomerate, making aluminium matrix composites with 13 a uniform dispersion of the nano-particles using liquid routes is an exceptionally difficult task. In this 14 study, an innovative approach was utilised to prevent agglomeration of nano-particles by 15encapsulating SiC nano-particles using graphene sheets during ball milling. Subsequently, the milled 16 mixture was incorporated into A356 molten alloy using non-contact ultrasonic vibration method. Two 17 different shapes for graphene sheets were characterised using HRTEM, including onion-like shells 18encapsulating SiC particles and disk-shaped graphene nanosheets. This resulted in 45% and 84% 19improvement in yield strength and tensile ductility, respectively. The former was ascribed to the 20Orowan strengthening mechanism, while the latter is due primarily to the fiber pull-out mechanism, 21 brought about by the alteration of the solidification mechanism from particle pushing to particle

An Overview of Metal Matrix Nanocomposites Reinforced with Graphene Nanoplatelets; Mechanical, Electrical and Thermophysical Properties

“…Over the last decade, several efforts have been carried out to fabricate AMCs reinforced by various nano and micron ceramic particles through different fabrication techniques. For example, Al-Al 2 O 3 by SPS [112], Al-B 4 C by SPS and reactive infiltration [113,114], Al-MgO by stir casting and powder metallurgy [115], Al-SiC by pressureless infiltration, casting, powder metallurgy and extrusion process [116][117][118]. However, there is a large volume of published studies describing the role of different allotropes of carbon on mechanical properties of the AMCs and some of these efforts are listed in the following 61le ( Table 2).…”

Mechanical and tribological behaviours of aluminium hybrid composites reinforced by CDA-B4C

“…Aluminium being a ductile material turns brittle when hard ceramics are added in the matrix which enhances the hardness. Uniform distribution of reinforcements, rate of solidification, density of reinforcement particle and less porosity are few parameters which influences the hardness of composites [23,48].…”

Microstructure and mechanical properties of graphene-reinforced aluminum-matrix composites

“…3,16 These exceptional properties make it a perfect reinforcement for metal-matrix composites. A lot of research work has been carried out for the fabrication of aluminium composites reinforced with graphene nanosheets, [17][18][19] graphene nanoflakes, [18][19][20][21] few-layered graphene, 22 or its derivatives such as graphene oxide and reduced graphene oxide. 23,24 Cold compaction followed by hot isostatic pressing, 18 as well as hot extrusion, 17,24,20,21 vacuum hot press and/or hot rolling 22 are commonly used, according to the literature, to manufacture solid pure aluminium and graphene-reinforced aluminium-matrix composite specimens.…”