scholarly journals Development and Characterization of Mg-SiC Nanocomposite Powders Synthesized by Mechanical Milling

2017 ◽  
Vol 742 ◽  
pp. 165-172 ◽  
Author(s):  
Daniela Penther ◽  
Claudia Fleck ◽  
Alireza Ghasemi ◽  
Ralf Riedel ◽  
Sepideh Kamrani
Keyword(s):  
Mechanical Milling ◽  
Volume Fraction ◽  
High Volume ◽  
Average Diameter ◽  
High Energy ◽  
Particle Size Analysis ◽  
Milling Process ◽  
Size Analysis ◽  
Magnesium Matrix ◽  
Nanocomposite Powders

Magnesium powder in micron scale and various volume fractions of SiC particles with an average diameter of 50 nm were co-milled by a high energy planetary ball mill for up to 25 h to produce Mg-SiC nanocomposite powders. The milled Mg-SiC nanocomposite powders were characterized by scanning electron microscopy (SEM) and laser particle size analysis (PSA) to study morphological evolutions. Furthermore, XRD, TEM, EDAX and SEM analyses were performed to investigate the microstructure of the magnesium matrix and distribution of SiC-reinforcement. It was shown that with addition of and increase in SiC nanoparticle content, finer particles with narrower size distribution are obtained after mechanical milling. The morphology of these particles also became more equiaxed at shorter milling times. The microstructural observation revealed that the milling process ensured uniform distribution of SiC nanoparticles in the magnesium matrix even with a high volume fraction, up to 10 vol%.

Effect of SiC Nanoparticles Content and Milling Time on the Characteristics of Al/SiC Nanocomposite Powders Produced via Mechanical Milling

2013 ◽  
Vol 829 ◽  
pp. 505-509 ◽  
Author(s):  
Farshad Akhlaghi ◽  
Sareh Mosleh-Shirazi
Keyword(s):  
Crystal Size ◽  
Milling Time ◽  
Matrix Alloy ◽  
High Energy ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Sic Nanoparticles ◽  
Sic Particles ◽  
The Matrix ◽  
Nanocomposite Powders

In the present study high energy ball milling was utilized to produce aluminum (Al-6061) matrix nanocomposite powders reinforced with nanosilicon carbide (SiC) particles. The starting materials containing different percentages (1,3 or 5 wt.%) of nanoSiC particles (25-50 nm) and Al (38-63 μm) were co-milled for different times (16, 20, 24 h) to achieve nanocomposite powders. The crystal size of powders were evaluated by quantitative XRD analysis. Laser particle size analysis was used to evaluate the size of powders during milling. The microstructure of powders and their microhardness values were evaluated by Scanning Electron Microscopy (SEM) and a microhardness tester respectively. The results indicated that the crystal size of the matrix alloy decreased by milling time. The increased SiC content up to 3% resulted in increased microhardness of the powders. However, further increase of SiC to 5% resulted in decreased microhardness due to agglomeration. It was concluded that the maximum microhardness together with a uniform distribution of SiC particles within the matrix alloy was obtained after 20 h milling of powder mixture containing 3% of SiC nanoparticles.

scholarly journals Composite Compacts of Fe/Fe3O4 Type Obtained by Mechanical Milling-Sintering-Annealing Route

2015 ◽  
Vol 13 ◽  
pp. 3-8
Author(s):  
Traian Florin Marinca ◽  
Bogdan Viorel Neamţu ◽  
Ionel Chicinaş ◽  
Florin Popa ◽  
Petru Pascuta
Keyword(s):  
Mechanical Milling ◽  
High Energy ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Sintered Compact ◽  
X Ray ◽  
Before And After ◽  
Type Composite

Fe/Fe2O3composite powders were obtained by mechanical milling of iron and hematite up to 120 minutes in a high energy planetary ball mill. The particles size decreases by mechanical milling upon the formation of the Fe/Fe2O3composite particles. After 120 minutes of milling the median particles size is at 7.2 μm. The Fe/Fe3O4type composite were obtained by reactive sintering in argon atmosphere at 1100 °C of the Fe/Fe2O3composite powders milled for 60 and 120 minutes. After sintering a FeO-wüstite residual phase is formed and this phase is eliminated by applying a subsequent annealing at a temperature of 550 °C. The sintered compact before and after annealing is composed by a quasi-continuous iron matrix in which are embedded iron oxides clusters (Fe3O4and FeO before annealing and Fe3O4after annealing). The iron oxide clusters are analogous with the Widmanstatten structure observed in steels before and after annealing. The materials have been investigated using laser particle size analysis, optical microscopy, scanning electron microscopy, energy dispersive X-ray spectrometry and X-ray diffraction.

MICROSTRUCTURAL EVOLUTION DURING HIGH ENERGY MECHANICAL MILLING AND HEAT TREATMENT OF Cu-(5,10)vol.%Al2O3 NANOCOMPOSITE POWDERS

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1789-1795
Author(s):  
AAMIR MUKHTAR ◽  
DELIANG ZHANG ◽  
BRIAN GABBITAS ◽  
CHARLIE KONG ◽  
PAUL MUNROE
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Microstructural Evolution ◽  
Mechanical Milling ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
High Energy ◽  
Transmission Electron ◽  
Powder Particles ◽  
Nanocomposite Powders

Cu -(5-10) vol .% Al 2 O 3 nanocomposite powders were produced from a mixture of Cu powder and Al 2 O 3 nanopowder using a high energy mechanical milling (HEMM) route consisting of two stages. The microstructural evolution of the Cu – Al 2 O 3 nanocomposite powder particles (or granules) produced after first and the second stages of milling was studied using scanning electron microscopy (SEM), transmission electron microcopy (TEM), scanning transmission electron microscopy (STEM) and energy dispersive X-ray (EDX) mapping. The study confirmed that homogenous dispersion of Al 2 O 3 nanoparticles in the Cu matrix was achieved after the first stage of milling and the relatively large Al 2 O 3 particles were further broken into smaller nanoparticles after the second stage of milling. The milled nanocomposite powders were also heat treated at 150, 300, 400 and 500°C for 1 hour, respectively, to determine the microstructural changes of the powder particles as a function of annealing temperature. It was found that after heat treatment at 150°C, the Cu grain sizes decreased due to recrystallisation, and increasing the annealing temperature to 300°C causes slight coarsening of the Cu grains. Further increasing the annealing temperature to 500°C caused significant coarsening of the Cu grains and the Al 2 O 3 nanoparticles. It also appeared that the coarsening of Cu grains in the composite powder particles after annealing at 500°C become less severe with increasing the volume fraction of Al 2 O 3 particles.

Characterization of Al/SiC Nanocomposite Prepared by Mechanical Alloying Method

2007 ◽  
Vol 553 ◽  
pp. 257-265 ◽  
Author(s):  
Ali Shokuhfar ◽  
M.R. Dashtbayazi ◽  
M.R. Alinejad ◽  
Tolou Shokuhfar
Keyword(s):  
Particle Size ◽  
Mechanical Alloying ◽  
Research Work ◽  
High Energy ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Nanocomposite Powders

In this research work, a high-energy ball mill has been applied to prepare an Al/SiC nanocomposite. The formation mechanism of the nanocomposite was investigated. This nanocomposite contained the nanocrystalline characteristics. Crystallite size, lattice strain and particle size of the nanocomposite as a function of milling time were determined. SEM micrographs showed that the nanocomposite powders agglomerated after milling. The particle size analysis confirmed the agglomeration of the nanocomposite particles. TEM observations showed that the SiC particles were in the nanometer size and these particles embedded in the Al matrix, and the nanocomposite produced in the final stage of mechanical alloying. In addition, a simple model checked for the refinement of the crystallite and the particle size of nanocomposite.

scholarly journals Assessment of Physical, Microstructural, Thermal, Techno-Functional, And Rheological Characteristics of Apple (Malus Domestica) Seeds of Northern Himalayas

2021 ◽  
Author(s):  
Mehnaza Manzoor ◽  
Jagmohan Singh
Keyword(s):  
Energy Requirement ◽  
Geometric Mean ◽  
High Energy ◽  
Particle Size Analysis ◽  
Absorption Capacity ◽  
Size Analysis ◽  
Scanning Electron Micrographs ◽  
Seed Flour ◽  
Mean Diameter ◽  
Golden Delicious

Abstract The study examined the physical, morphological, thermal, techno-functional, and rheological properties of two apple seed cultivars viz: red delicious (RD) and golden delicious (GD). Physical properties showed that red delicious seeds were significantly (p≤0.05) different in width, geometric mean diameter, arithmetic mean diameter, volume, and surface area than golden delicious seeds. The proximate composition of RD seed flour showed a higher amount of crude protein and fat content than GD seed flour. RD seed flour was significantly different in L*, a*, b* values, bulk density, water/oil absorption capacity and the emulsifying ability than GD seed flour. From particle size analysis it was possible to found that GD was significantly (p≤0.05) lower than RD flour macromolecules. Scanning electron micrographs showed oval/spherical starch granules of small size embedded in a continuous protein matrix. Thermograph revealed exothermic transition enthalpy for both RD and GD seed flour, which indicates a high energy requirement for crystallite melting. The rheological assays revealed high elastic modulus (G′), of seed flours that will help in modifying the texture of foods. This study suggests the potential of apple seeds in the formulation of protein-enriched foods to combat malnutrition while contributing to the reduction in industrial wastage.

Emulsion Formation by Homogenization: Current Understanding and Future Perspectives

2019 ◽  
Vol 10 (1) ◽  
pp. 239-258 ◽  
Author(s):  
Andreas Håkansson
Keyword(s):  
Food Production ◽  
Scaling Laws ◽  
Scientific Literature ◽  
Volume Fraction ◽  
High Volume ◽  
High Energy ◽  
Current Understanding ◽  
Future Perspectives ◽  
Fundamental Understanding ◽  
Food Applications

Emulsion formation by homogenization is commonly used in food production and research to increase product stability and to design colloidal structures. High-energy methods such as high-pressure homogenizers and rotor–stator mixers are the two most common techniques. However, to what extent does the research community understand the emulsion formation taking place in these devices? This contribution attempts to answer this question through critically reviewing the scientific literature, starting with the hydrodynamics of homogenizers and continuing by reviewing drop breakup and coalescence. It is concluded that although research in this field has been ongoing for a century and has provided a substantial amount of empirical correlations and scaling laws, the fundamental understanding is still limited, especially in the case of emulsions with a high-volume fraction of the disperse phase, as seen in many food applications. These limitations in the current understanding are also used to provide future perspectives and suggest directions for further investigation.

The Effect of Reinforcement Phase on the Microstructure of Al-SiC Nanocomposite Powder Prepared via Mechanical Alloying

2009 ◽  
Vol 83-86 ◽  
pp. 764-770
Author(s):  
Taha Rostamzadeh ◽  
H. Shahverdi ◽  
R. Sarraf-Mamoory ◽  
A. Shanaghi
Keyword(s):  
Electron Microscopy ◽  
Mechanical Alloying ◽  
Metal Matrix ◽  
Milling Time ◽  
Lattice Strain ◽  
Volume Fraction ◽  
Aluminum Matrix ◽  
High Energy ◽  
Nanocomposite Powder ◽  
Nanocomposite Powders

Mechanical alloying is one of the most successful methods for the manufacturing of metal matrix nanocomposite powders. In this study, Al/SiC metal matrix composite (MMCp) powders with volume fractions of 5, 10, and 15 percent SiC were successfully obtained after milling the powder for a period of 25 hours at a ball to powder ratio of 15:1 using high energy planetary milling. The Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses were conducted to investigate the lattice strain of the matrix phase and the microstructure of the nanocomposite powders after 1, 10, and 25 hours of milling time. Also, the morphology of the Al-5%SiC nanocomposite powder was investigated using transmission electron microscopy (TEM). The results show that with the increase of both milling time and the reinforcement phase volume fraction, the lattice strain increases and the average size of aluminum phase crystallites decreases. Eventually, after 25 hours of milling, the nanocomposite powders show a spherical-like morphology and SiC particles were distributed in an aluminum matrix with appropriate order.

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