Nano-sized Ceramic Particles Research Articles

Microstructure and microhardness of SiC nanoparticles reinforced magnesium composites fabricated by ultrasonic method

The use of ultrasonic non-linear effects to disperse nano-sized ceramic particles in molten metal has been studied and nano-sized SiC particle reinforced AZ91D magnesium composites were fabricated. The microstructure of the composites was investigated by high-resolution scanning electron microscopy (SEM), X-ray photo spectroscopy (XPS), and high-resolution X-ray diffractometer (XRD) techniques. Experimental results show a nearly uniform distribution and good dispersion of the SiC nanoparticles within the magnesium matrix, although some of small agglomerates (less than 300 nm) were found in matrix. Detailed study reveals that the SiC nanoparticles were partially oxidized. The microhardness of composites have been improved significantly compared to that of pure AZ91D. The interaction between SiC nanoparticles and the matrix was investigated. The interaction between ultrasonic waves and nanoparticles was also discussed. The ultrasonic fabrication methodology is striking to rapidly produce a wide range of nano-sized particles reinforced metal matrix composites.

Microstructure and microhardness of SiC nanoparticles reinforced magnesium composites fabricated by ultrasonic method

Abstract The use of ultrasonic non-linear effects to disperse nano-sized ceramic particles in molten metal has been studied and nano-sized SiC particle reinforced AZ91D magnesium composites were fabricated. The microstructure of the composites was investigated by high-resolution scanning electron microscopy (SEM), X-ray photo spectroscopy (XPS), and high-resolution X-ray diffractometer (XRD) techniques. Experimental results show a nearly uniform distribution and good dispersion of the SiC nanoparticles within the magnesium matrix, although some of small agglomerates (less than 300 nm) were found in matrix. Detailed study reveals that the SiC nanoparticles were partially oxidized. The microhardness of composites have been improved significantly compared to that of pure AZ91D. The interaction between SiC nanoparticles and the matrix was investigated. The interaction between ultrasonic waves and nanoparticles was also discussed. The ultrasonic fabrication methodology is striking to rapidly produce a wide range of nano-sized particles reinforced metal matrix composites.

Study on bulk aluminum matrix nano-composite fabricated by ultrasonic dispersion of nano-sized SiC particles in molten aluminum alloy

Abstract Lightweight metal matrix nano-composites (MMNCs) (metal matrix with nano-sized ceramic particles) can be of significance for automobile, aerospace and numerous other applications. It would be advantageous to produce low-cost as-cast bulk lightweight components of MMNCs. However, it is extremely difficult to disperse nano-sized ceramic particles uniformly in molten metal. This paper presents a new method for an inexpensive fabrication of bulk lightweight MMNCs with reproducible microstructures and superior properties by use of ultrasonic nonlinear effects, namely transient cavitation and acoustic streaming, to achieve uniform dispersion of nano-sized SiC particles in molten aluminum alloy A356. Microstructural study was carried out with an optical microscope, SEM, EDS mapping, and XPS. It validates a good dispersion of nano-sized SiC in metal matrix. It also indicates that partial oxidation of SiC nanopartilces results in the formation of SiO2 in the matrix. Mechanical properties of the as-cast MMNCs have been improved significantly even with a low weight fraction of nano-sized SiC. The ultrasonic fabrication methodology is promising to produce a wide range of other MMNCs.

Sintering Characteristics of Nano-Ceramic Coatings

This paper concentrates on sintering characteristics of nano-sized ceramic SiO2 particles. The sintering process is studied as a function of temperature using a conventional furnace and using a laser beam. The underlying idea is to combine the nanoceramic sol-gel concept with inkjet technology and laser treatment. A solution containing nano-sized ceramic particles is fed to an inkjet nozzle that generates a software-controlled pattern on a surface. Afterwards the drops are exposed to an intense laser beam that gives rise to drying and densification of the drops, thereby forming a sintered ceramic layer. The question addressed in the paper is whether the laser treatment leads to the same densified layers as obtained with conventional heat treatments. It turns out that the morphologies are similar but that laser treatment provides much faster the same results.

Ion transport in polymer electrolytes containing nanoparticulate TiO2: The influence of polymer morphology

Recent studies have shown that composite polymer electrolytes, formed by dispersing nanosized ceramic particles in polyether-based electrolytes, have improved ion transport properties as compared to their unfilled analogues. In the present study polymer electrolytes with different loadings of nano-sized ceramic particles (TiO2) and different polymer chemistry and morphology have been investigated. Of special interest are filler induced effects on polymer, solvent and cationic mobility. Partly crystalline polymer electrolytes based on poly(ethylene oxide) have been compared to fully amorphous polymer electrolytes based on a polyether urethane, as well as gel electrolytes based on PMMA. 7Li pfg-NMR, linewidth and spin–spin relaxation times as well as 1H pfg-NMR and spin–spin relaxation times, were measured as a function of temperature and composition. The 1H spin–spin relaxation measurements reveal increased average polymer mobility with the addition of filler up to a maximum at 4 and 8 wt.% TiO2 for the fully amorphous and the partly crystalline electrolytes, respectively. The 7Li linewidth measurements for the fully amorphous system show a broadening of the linewidth with addition of filler. Based on variable temperature measurements this broadening is interpreted as a result of the inhomogeneity introduced by the filler particles. Pulsed field gradient (pfg) diffusion measurements were employed to determine ion and solvent self-diffusion coefficients. In the case of the PMMA-based gel electrolyte and the fully amorphous electrolytes enhanced cation self-diffusion was observed upon addition of TiO2.

Elektrophoretische Abscheidung zur Herstellung von faserverstärkten Keramik- und Glasmatrix-Verbundwerkstoffen — Eine Übersicht

In this paper, we review the application of the electrophoretic deposition (EPD) technique in the fabrication of fibre reinforced composites, with particular emphasis on composites with glass and ceramic matrices containing metallic or ceramic fibre fabric reinforcement. The review covers research published in the last 10 years. EPD has been used to infiltrate preforms with tight fibre weave architectures using different nano-sized ceramic particles, including silica and boehmite sols, as well as dual-component sols of mullite composition. The principles of the EPD technique are briefly explained and various factors affecting the EPD behaviour of ceramic sols and their optimisation to obtain high infiltration of the fibre preforms are considered. Overall, the analysis of the published data and the results of the authors demonstrate that EPD, being simple and inexpensive, provides an attractive alternative for ceramic infiltration and coating of fiber fabrics, even if they exhibit tight fibre weave architectures.

Structural Study of Nano-Size Ceramic Particles Fabricated by Cavitation

Structural Study of Nano-Size Ceramic Particles Fabricated by Cavitation

Structural Study of Nano-Size Ceramic Particles Fabricated by Cavitation

Structural Study of Nano-Size Ceramic Particles Fabricated by Cavitation