scholarly journals Ultrasonically Stir Cast SiO2/A356 Metal Matrix Nanocomposites

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2004
Author(s):  
Massoud Malaki ◽  
Alireza Fadaei Tehrani ◽  
Behzad Niroumand ◽  
Amir Abdullah

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.

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1034
Author(s):  
Massoud Malaki ◽  
Alireza Fadaei Tehrani ◽  
Behzad Niroumand ◽  
Manoj Gupta

Metal matrix composites (MMCs) have been developed in response to the enormous demand for special industrial materials and structures for automotive and aerospace applications, wherein both high-strength and light weight are simultaneously required. The most common, inexpensive route to fabricate MMCs or metal matrix nanocomposites (MMNCs) is based on casting, wherein reinforcements like nanoceramics, -carbides, -nitrides, elements or carbon allotropes are added to molten metal matrices; however, most of the mentioned reinforcements, especially those with nanosized reinforcing particles, have usually poor wettability with serious drawbacks like particle agglomerations and therefore diminished mechanical strength is almost always expected. Many research efforts have been made to enhance the affinity between the mating surfaces. The aim in this paper is to critically review and comprehensively discuss those approaches/routes commonly employed to boost wetting conditions at reinforcement-matrix interfaces. Particular attention is paid to aluminum matrix composites owing to the interest in lightweight materials and the need to enhance the mechanical properties like strength, wear, or creep resistance. It is believed that effective treatment(s) may enormously affect the wetting and interfacial strength.


2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Payodhar Padhi ◽  
Sachikanta Kar

Addition of nano particles, even in quantities as small as 2 weight percent can enhance the hardness or yield strength by a factor as high as 2. There are several methods for the production of metal matrix nanocomposites including mechanical alloying, vertex process, and spray deposition and so forth. However, the above processes are expensive. Solidification processing is a relatively cheaper route. During solidification processing, nano particulates tend to agglomerate as a result of van der Waals forces and thus proper dispersion of the nano particulate in metal matrix is a challenge. In the present study a noncontact method, where the ultrasonic probe is not in direct contact with the liquid metal, was attempted to disperse nanosized SiC particulates in aluminum matrix. In this method, the mold was subjected to ultrasonic vibration. Hardness measurements and microstructural studies using HRTEM were carried out on samples taken from different locations of the nanocomposite ingot cast by this method.


Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2823 ◽  
Author(s):  
Mehran Dadkhah ◽  
Abdollah Saboori ◽  
Paolo Fino

Two-dimensional graphene plateletes with unique mechanical, electrical and thermo-physical properties could attract more attention for their employed as reinforcements in the production of new metal matrix nanocomposites (MMNCs), due to superior characteristics, such as being lightweight, high strength and high performance. Over the last years, due to the rapid advances of nanotechnology, increasing demand for the development of advanced MMNCs for various applications, such as structural engineering and functional device applications, has been generated. The purpose of this work is to review recent research into the development in the powder-based production, property characterization and application of magnesium, aluminum, copper, nickel, titanium and iron matrix nanocomposites reinforced with graphene. These include a comparison between the properties of graphene and another well-known carbonaceous reinforcement (carbon nanotube), following by powder-based processing strategies of MMNCs above, their mechanical and tribological properties and their electrical and thermal conductivities. The effects of graphene distribution in the metal matrices and the types of interfacial bonding are also discussed. Fundamentals and the structure–property relationship of such novel nanocomposites have also been discussed and reported.


Author(s):  
Heping Liu ◽  
Shiyu Zhou ◽  
Xiaochun Li

Metal matrix nanocomposites (MMNCs) are produced by dispersing reinforcing nanoparticles into metal matrix. It is a type of emerging materials with high strength and light weight and draws significant attentions in recent years. If the particles are not well dispersed, they will form particle clusters in the metal matrix. These clusters will detrimentally impact on the final quality of MMNCs. This paper proposes a statistical approach to estimating the parameters of the size distribution of clusters in MMNCs. One critical challenge is that the clusters are distributed in a three-dimensional (3D) space, while the observations we have are two-dimensional (2D) cross-section microscopic images of these clusters. In the proposed approach, we first derived the probability distribution of the observed sizes of the 2D cross sections of the clusters and then a maximum likelihood estimation (MLE) method is developed to estimate the 3D cluster size distribution. Computational efficient algorithms are also established to make computational load manageable. The case studies based on simulation and real observed data are conducted, which demonstrates the effectiveness of the proposed approach.


2015 ◽  
Vol 813-814 ◽  
pp. 625-628
Author(s):  
A. Nandakumar ◽  
D. Dinakaran

Metal Matrix nanoComposites (MMNC) refer to materials consisting of a ductile metal or alloy matrix in which some nanosized reinforcement materials is implanted. These materials combine metal and ceramic features, i.e., ductility and toughness with high strength. Thus, metal matrix nanocomposites are suitable for production of materials with high strength in shear/compression processes and high service temperature capabilities. Both Metal Matrix Composite (MMC) and Ceramic Matrix Composites (CMC) with Carbon nanoTubes (CNT) nanocomposites hold promise, but also pose challenges for real success. In the present paper deals an inclusive review of literature in effect of nanoparticles in reinforced metal matrix composites on the machinability characteristics of the composite materials.


Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 330 ◽  
Author(s):  
Massoud Malaki ◽  
Wenwu Xu ◽  
Ashish Kasar ◽  
Pradeep Menezes ◽  
Hajo Dieringa ◽  
...  

Lightweight high-strength metal matrix nano-composites (MMNCs) can be used in a wide variety of applications, e.g., aerospace, automotive, and biomedical engineering, owing to their sustainability, increased specific strength/stiffness, enhanced elevated temperature strength, improved wear, or corrosion resistance. A metallic matrix, commonly comprising of light aluminum or magnesium alloys, can be significantly strengthened even by very low weight fractions (~1 wt%) of well-dispersed nanoparticles. This review discusses the recent advancements in the fabrication of metal matrix nanocomposites starting with manufacturing routes and different nanoparticles, intricacies of the underlying physics, and the mechanisms of particle dispersion in a particle-metal composite system. Thereafter, the microstructural influences of the nanoparticles on the composite system are outlined and the theory of the strengthening mechanisms is also explained. Finally, microstructural, mechanical, and tribological properties of the selected MMNCs are discussed as well.


Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 125
Author(s):  
Seyed Kiomars Moheimani ◽  
Mehran Dadkhah ◽  
Mohammad Hossein Mosallanejad ◽  
Abdollah Saboori

Metal matrix nanocomposites (MMNCs) with high specific strength have been of interest for numerous researchers. In the current study, Mg matrix nanocomposites reinforced with AlN nanoparticles were produced using the mechanical stirring-assisted casting method. Microstructure, hardness, physical, thermal and electrical properties of the produced composites were characterized in this work. According to the microstructural evaluations, the ceramic nanoparticles were uniformly dispersed within the matrix by applying a mechanical stirring. At higher AlN contents, however, some agglomerates were observed as a consequence of a particle-pushing mechanism during the solidification. Microhardness results showed a slight improvement in the mechanical strength of the nanocomposites following the addition of AlN nanoparticles. Interestingly, nanocomposite samples were featured with higher electrical and thermal conductivities, which can be attributed to the structural effect of nanoparticles within the matrix. Moreover, thermal expansion analysis of the nanocomposites indicated that the presence of nanoparticles lowered the Coefficient of Thermal Expansion (CTE) in the case of nanocomposites. All in all, this combination of properties, including high mechanical strength, thermal and electrical conductivity, together with low CTE, make these new nanocomposites very promising materials for electro packaging applications.


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