scholarly journals PHYSICO-CHEMICAL INTERACTIONS BETWEEN COMPONENTS OF THE Al/SiO2 SYSTEM IN METALLURGICAL SYNTHETIC PROCESSES OF CASTING PARTICULATE REINFORCED ALUMINUM ALLOYS

2017 ◽  
pp. 31-39 ◽  
Author(s):  
I. V. Rafalski ◽  
B. M. Nemenenok
Keyword(s):  
Silicon Oxide ◽  
Liquid Aluminum ◽  
Aluminum Matrix ◽  
Oxide Ceramics ◽  
Dispersed Particles ◽  
Physicochemical Interactions ◽  
Physico Chemical ◽  
Particulate Reinforced ◽  
Spontaneous Wetting ◽  
Temperature Time

The physicochemical interactions between components in the Al/SiO2aluminum matrix compositions under various temperature conditions of processing are studied. The synthesis of aluminum oxide ceramics in aluminum melts for the production of particulate reinforced Al-Si/Al2O3alloys was performed. The addition of dispersed particles of silicon oxide ceramics was carried out by mixing into aluminum melt in a liquid-solid state. At the temperature-time processing of the Al/SiO2compositions, alumina ceramic with a contact surface layer providing spontaneous wetting with liquid aluminum is realized.

Aluminum-Matrix Aluminum Nitride Particle Composite as a Low-Thermal-Expansion Thermal Conductor

1993 ◽  
Vol 323 ◽  
Author(s):  
Shy-Wen Lai ◽  
D. D. L. Chung
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Thermal Expansion ◽  
Volume Fraction ◽  
Liquid Aluminum ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Low Thermal Expansion ◽  
Increasing Temperature

AbstractAluminum-matrix composites containing AIN or SiC particles were fabricated by vacuum infiltration of liquid aluminum into a porous particulate preform under an argon pressure of up to 41 MPa. Al/AIN was superior to Al/SiC in thermal conductivity. At 59 vol.% AIN, Al/AlN had a thermal conductivity of 157 W/m. °C and a thermal expansion coefficient of 9.8 × 10−-6°C−1 (35–100 °C). Al/AlN had similar tensile strength and higher ductility compared to Al/SiC of a similar reinforcement volume fraction at room temperature, but exhibited higher tensile strength and higher ductility at 300–400°C. The ductility of Al/AlN increased with increasing temperature from 22 to 400°C, while that of Al/SiC did not change with temperature. The superior high temperature resistance of Al/AlN is attributed to the lack of a reaction between Al and AIN, in contrast to the reaction between Al and SiC in AI/SiC.

Determination of the elastic modulus of microscale ceramic particles via nanoindentation

2004 ◽  
Vol 19 (8) ◽  
pp. 2437-2447 ◽  
Author(s):  
J.W. Leggoe
Keyword(s):  
Elastic Modulus ◽  
Elastic Moduli ◽  
Aluminum Matrix ◽  
Scalar Particle ◽  
Accurate Estimate ◽  
Flat Punch ◽  
Silicon Carbide Particles ◽  
Material Mismatch ◽  
Particulate Reinforced

Nanoindentation of the reinforcement in a particulate reinforced metal matrix composite (PR MMC) enables direct investigation of reinforcement properties within the finished material. Mismatch between the elastic moduli of the reinforcement and matrix creates a “secondary indentation” effect, whereby the stiffer reinforcement particles themselves “indent” the more compliant matrix. A finite-element investigation was undertaken to quantify the additional penetration arising under secondary indentation for spherical and cylindrical particles. Modification of Sneddon’s equation for a flat punch by a scalar particle shape factor provided an accurate estimate of the additional penetration. The modified equation was combined with the analysis of Field and Swain to extract the particle elastic modulus from results obtained using a spherical indenter under a multiple partial-unloading indentation regime. The resulting methodology was used to determine the elastic moduli of silicon carbide particles and MicralTM microspheres in two aluminum-matrix PR MMCs.

scholarly journals MRI Relaxivity Changes of the Magnetic Nanoparticles Induced by Different Amino Acid Coatings

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 394 ◽  
Author(s):  
Iryna Antal ◽  
Oliver Strbak ◽  
Iryna Khmara ◽  
Martina Koneracka ◽  
Martina Kubovcikova ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Chemical Properties ◽  
Hydrodynamic Diameter ◽  
Contrast Imaging ◽  
Dispersed Particles ◽  
Physico Chemical ◽  
The One ◽  
Molecular Contrast ◽  
The Impact ◽  
Positively Charged

In this study, we analysed the physico-chemical properties of positively charged magnetic fluids consisting of magnetic nanoparticles (MNPs) functionalised by different amino acids (AAs): glycine (Gly), lysine (Lys) and tryptophan (Trp), and the influence of AA–MNP complexes on the MRI relaxivity. We found that the AA coating affects the size of dispersed particles and isoelectric point, as well as the zeta potential of AA–MNPs differently, depending on the AA selected. Moreover, we showed that a change in hydrodynamic diameter results in a change to the relaxivity of AA–MNP complexes. On the one hand, we observed a decrease in the relaxivity values, r1 and r2, with an increase in hydrodynamic diameter (the relaxivity of r1 and r2 were comparable with commercially available contrast agents); on the other hand, we observed an increase in r2* value with an increase in hydrodynamic size. These findings provide an interesting preliminary look at the impact of AA coating on the relaxivity properties of AA–MNP complexes, with a specific application in molecular contrast imaging originating from magnetic nanoparticles and magnetic resonance techniques.

Dry sliding wear of a Ti50Ni25Cu25 particulate-reinforced aluminum matrix composite

1998 ◽  
Vol 29 (6) ◽  
pp. 1741-1747 ◽  
Author(s):  
G. Wang ◽  
P. Shi ◽  
M. Qi ◽  
F. X. Chen ◽  
D. Z. Yang ◽  
...  
Keyword(s):  
Matrix Composite ◽  
Sliding Wear ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composite ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Particulate Reinforced
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