Ultrasonically Stir Cast SiO2/A356 Metal Matrix Nanocomposites

Massoud Malaki,Alireza Fadaei Tehrani,Amir Abdullah,Behzad Niroumand

doi:10.3390/met11122004

Massoud Malaki, Alireza Fadaei Tehrani + Show 2 more

Open Access

https://doi.org/10.3390/met11122004

Copy DOI

Abstract

Metal matrix nanocomposites are a newly developed materials with promising applications in a wide variety of areas, ranging from medical to aerospace structures, owing to their lightweight high-strength properties. A light metal like aluminum is usually strengthened by a reinforcing agent of carbides, nitrides, oxides, carbon-based materials, or even elementals to boost the mechanical performance without sacrificing lightweight; however, almost all reinforcing nanomaterials are commonly poorly wetted by metals leading to agglomerations, clusterings, among other problems, with diminished ductility and overall mechanical performance. To tackle the mentioned problems, a number of strategies including coatings, thermal, mechanical, or chemical treatments may be followed. In the present study, a particular focus is paid on the mechanical dispersion of nano-silica particles in a molten A356 alloy through applying high-intensity ultrasonic agitations in order to improve dispersibility, wettability, and interfacial affinity. Nano-silica being an inexpensive high-strength nanomaterial is added to an A356 aluminum alloy melt and then dispersed and distributed by a 2-kW power ultrasonic system. Experimental results including microscopic observations and those mechanical experimentations revealed that the ultrasonication of the aforesaid solid–liquid system may greatly improve the affinity between the de-agglomerated nano-silica particles and the host aluminum matrix with enhanced ductility.

Highlights

Metal matrix composites (MMCs) and nanocomposites (MMNCs), especially those produced by casting, are a class of advanced materials and structures with great potentials to be used in critical applications
Stir-cast MMCs or matrix com or nanocomposites (MMNCs) are of those lightweight, high-strength composite materials with common applications in automotive and aerospace structures; they basically are referred to a type of composite materials with at least two constituents: (i) a light metal such as aluminum or magnesium and (ii) a reinforcing agent like carbon-based nanomaterials, ceramics, or carbides, to name a few [3]
The amounts of 2.0, 4.0, and 6.0 gr silica nano-powder were added to gr A356 aluminum alloy with the chemical composition given in Table 1 being sup a 1600 gr A356 aluminum alloy with the chemical composition given in Table 1 being by the Materials

Summary

Introduction

Metal matrix composites (MMCs) and nanocomposites (MMNCs), especially those produced by casting, are a class of advanced materials and structures with great potentials to be used in critical applications. Many disadvantages with conventional composites, i.e., MMCs, including inferior mechanical performance, poor machinability, insignificant wear resistance, and microstructural inhomogeneity can be circumvented if nano-sized reinforcing material is properly employed [4,5]. It was revealed, for example, that the values of hardness, yield strength (YS), and ultimate tensile strength (UTS) can be respectively improved by ~40%, 35%, and 21.5% only if the host

Objectives

Methods

Conclusion