Contribution of Orowan strengthening effect in particulate-reinforced metal matrix nanocomposites

807

305

Metal matrix composites reinforced by nano-particles are very promising materials, suitable for a large number of applications. These composites consist of a metal matrix filled with nano-particles featuring physical and mechanical properties very different from those of the matrix. The nano-particles can improve the base material in terms of wear resistance, damping properties and mechanical strength. Different kinds of metals, predominantly Al, Mg and Cu, have been employed for the production of composites reinforced by nano-ceramic particles such as carbides, nitrides, oxides as well as carbon nanotubes. The main issue of concern for the synthesis of these materials consists in the low wettability of the reinforcement phase by the molten metal, which does not allow the synthesis by conventional casting methods. Several alternative routes have been presented in literature for the production of nano-composites. This work is aimed at reviewing the most important manufacturing techniques used for the synthesis of bulk metal matrix nanocomposites. Moreover, the strengthening mechanisms responsible for the improvement of mechanical properties of nano-reinforced metal matrix composites have been reviewed and the main potential applications of this new class of materials are envisaged.

Section: Strengthening Mechanismsmentioning

confidence: 99%

Section: Load Transfer Effectmentioning

confidence: 99%

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Metal Matrix Composites Reinforced by Nano-Particles—A Review

Casati

Vedani

2014

807

305

“…This strengthening effect can be achieved through the different mechanisms including load transfer effect, Hall-Petch strengthening, thermal expansion coefficient mismatch and Orowan looping. Hence, in the previous works, the effect of different strengthening mechanisms is explained using models that can be used to forecast the yield strength [93][94][95][96][97][98]. strengthening mechanisms is explained using models that can be used to forecast the yield strength [93][94][95][96][97][98].…”

Section: Mechanical Propertiesmentioning

confidence: 99%

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

Saboori

Dadkhah

Fino

et al. 2018

Two-dimensional graphene nanoplatelets with unique electrical, mechanical and thermophysical characteristics are considered as an interesting reinforcement to develop new lightweight, high-strength, and high-performance metal matrix nanocomposites. On the other hand, by the rapid progress of technology in recent years, development of advanced materials like new metal matrix nanocomposites for structural engineering and functional device applications is a priority for various industries. This article provides an overview of research efforts with an emphasis on the fabrication and characterization of different metal matrix nanocomposites reinforced by graphene nanoplatelets (GNPs). Particular attention is devoted to find the role of GNPs on the final electrical and thermal conductivity, the coefficient of thermal expansion, and mechanical responses of aluminum, magnesium and copper matrix nanocomposites. In sum, this review pays specific attention to the structure-property relationship of these novel nanocomposites.

“…It is obvious that adding 10% of SiC nanoparticles into the aluminum matrix improves the strength and deformation behavior of the struts. According to the Orowan strengthening mechanism, the nano SiC particles act as stiff obstacles, preventing the dislocation movement and the dislocation lines that can only bypass them at higher loading stresses [29,30]. Hence, SiC increases the overall strength of the aluminum matrix of the struts.…”

Section: Compressive Propertiesmentioning

confidence: 99%

Melt Processing and Characterization of Al-SiC Nanocomposite, Al, and Mg Foam Materials

Nabawy

Khalil

Al-Ahmari

et al. 2016

Abstract:In the present work, metallic foams of Al, Mg and an Al-SiC nanocomposite (MMNC) have been fabricated using a new manufacturing technique by employing melt infiltration assisted with an electromagnetic force. The aim of this investigation was to study and to develop a reliable manufacturing technique consisting of different types of metallic foams. In this technique, an electromagnetic force was used to assist the infiltration of Al-SiC slurry and of pure liquid metal into a leachable pattern of NaCl, thus providing perfect cellular structures with micro-sized porosities. A high frequency induction coil unit equipped with a vacuum chamber and a hydraulic press was used to manufacture the foam materials. Microstructures of the produced foam materials were explored by using Field Emission Scanning Electron Microscopy (FESEM). The mechanical behavior of the manufactured foams was investigated by applying compression testing. The results indicate a high applicability of the new technique in producing metallic foams of pure metals and of a metal matrix nanocomposite . The produced foam materials displayed isotropic cellular structures with excellent compressive behaviors. Microstructure measurements indicate that the average pore size and strut thickness that can be achieved are in the ranges of 100-500 µm and 50-100 µm, respectively. The produced foam of the Al-SiC nanocomposite material provided the highest strength of 50 MPa prior to the densification stage, which equates to 25 times, and 10 times higher than the strength levels that were obtained by Al, and Mg foams, respectively.