Solute Content and the Tensile Behavior of High Pressure Die Cast Mg-Al Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 333-336 ◽  
Author(s):  
A.V. Nagasekhar ◽  
Carlos H. Cáceres
Keyword(s):  
Volume Fraction ◽  
Cell Structure ◽  
Al Alloys ◽  
Core Region ◽  
Aluminium Content ◽  
Solute Content ◽  
The Core ◽  
Β Phase ◽  
Intermetallic Particles ◽  
Phase Intermetallic

Binary Mg-Al alloys with varying content of aluminium from 0.5 to 12mass% have been studied. The proof stress increase in two steps whereas the ductility exhibits two correlated stepwise drops, as the aluminium content increases. The first increase in strength, and attendant drop in ductility, is observed between 4 and 5 mass% Al. The second stepwise change is observed between 10 and 12 mass% Al. These effects are connected with well defined changes in the microstructure: at 4 mass% a dispersion of β-phase intermetallic particles appears in the core region and a closed cell structure develops near the surface; at 12 mass% Al, the increased volume fraction of the β- phase intermetallics extends the interconnected network of intermetallics to include the core region as well. The micromechanics of the strengthening and decreased ductility are discussed.

scholarly journals Microbands in 80% Drawn Copper Single Crystals With and Starting Orientations

Texture ◽  
1975 ◽  
Vol 2 (1) ◽  
pp. 17-34 ◽  
Author(s):  
S. Horiuchi ◽  
K. Asakura ◽  
G. Wassermann ◽  
J. Grewen
Keyword(s):  
Single Crystals ◽  
Cross Section ◽  
Cell Structure ◽  
Core Region ◽  
Degree Of Deformation ◽  
The Core ◽  
Drawing Direction ◽  
Stable Orientation ◽  
Copper Single Crystals ◽  
High Degree

Copper single crystals with the starting orientations <111> and <100> were drawn 80%. In the core region of the rods the orientations and the microstructures were investigated. The stable <111> crystal had a structure consisting of equiaxed cells and microbands which were formed parallel to the {111} planes with the exception of the {111} plane in the cross section of the rod. The <100> orientation was not entirely stable; the beginning of some orientational changes was observed at a high degree of deformation. In the parts with stable orientation a cylindrical cell structure was found with the long axes parallel to the drawing direction. Single microbands formed locally. Dislocation tangles around them finally developed, which lead to a change of the <100> orientation.

Erosion in the Rectangular Biomass Circulating Fluidized Bed

2012 ◽  
Vol 608-609 ◽  
pp. 214-219
Author(s):  
Jing Hui Song ◽  
Tao Wang ◽  
Jing Gao ◽  
Xian Bin Xiao ◽  
Chang Qing Dong ◽  
...  
Keyword(s):  
Circulating Fluidized Bed ◽  
Volume Fraction ◽  
Rectangular Cross Section ◽  
Core Region ◽  
Front Wall ◽  
Back Wall ◽  
Left Wall ◽  
Phase Volume Fraction ◽  
The Core

Through MFIX software, a three-dimensional numerical gas-solid flow models without chemical reactions is developed to the distributions of solids phase volume fraction and velocities in a 220t/h rectangular cross-section biomass CFB with a height of 3m. The maximum of erosion occurs at the near-wall side at y=0.95m on the front-wall and back-wall. In transition region(0.8-1.4m) of the left-wall and right-wall, typical core-annular regime can be observed, particle in the core region have the tendency to move to the corner. The maximum of erosion occurs at the corner formed between the walls in the role of downward movement of particle. And the lateral movement of particles are obvious enhanced between the core region and back-wall in the role of exit effect, which lead a certain degree of lateral erosion between the core region and back-wall at the left-wall and right-wall.

Intramitochondrial Viruses of Reptilian Cell Origin

1972 ◽  
Vol 30 ◽  
pp. 318-319
Author(s):  
Philip D. Lunger ◽  
H. Fred Clark
Keyword(s):  
Particle Production ◽  
Outer Zone ◽  
Density Variation ◽  
Core Region ◽  
Mitochondrial Membranes ◽  
Virus Particles ◽  
The Core ◽  
Vipera Russelli ◽  
Maturation Stages ◽  
Type Particle

In the course of fine structure studies of spontaneous “C-type” particle production in a viper (Vipera russelli) spleen cell line, designated VSW, virus particles were frequently observed within mitochondria. The latter were usually enlarged or swollen, compared to virus-free mitochondria, and displayed a considerable degree of cristae disorganization.Intramitochondrial viruses measure 90 to 100 mμ in diameter, and consist of a nucleoid or core region of varying density and measuring approximately 45 mμ in diameter. Nucleoid density variation is presumed to reflect varying degrees of condensation, and hence maturation stages. The core region is surrounded by a less-dense outer zone presumably representing viral capsid.Particles are usually situated in peripheral regions of the mitochondrion. In most instances they appear to be lodged between loosely apposed inner and outer mitochondrial membranes.

Moire Fringes on Precipitates in Quenched and Aged Beryllium

1968 ◽  
Vol 26 ◽  
pp. 426-427
Author(s):  
F. J. Fraikor ◽  
A. W. Brewer
Keyword(s):  
Ternary Phase ◽  
Volume Fraction ◽  
Age Hardening ◽  
Orientation Relationships ◽  
Solute Content ◽  
Moiré Fringes ◽  
Moire Patterns ◽  
Total Volume Fraction ◽  
Diffraction Patterns ◽  
Moiré Patterns

A number of investigators have examined moire patterns on precipitate particles in various age-hardening alloys. For example, Phillips has analyzed moire fringes at cobalt precipitates in copper and Von Heimendahl has reported on moire fringes in the system Al-Au. Recently, we have observed moire patterns on impurity precipitates in beryllium quenched in brine from 1000°C and aged at various temperatures in the range of 500-800°C. This heat treatment of beryllium rolled from vacuum cast ingots produces the precipitation of both an fee ternary phase, AlFeBe4, and an hcp binary phase, FeBe11. However, unlike a typical age-hardening alloy, the solute content of this material is low (less than 1000 ppm of Fe and 600 ppm of Al) and hence the total volume fraction of precipitates is small. Therefore there is some difficulty in distinguishing the precipitates and their orientation relationships with the beryllium matrix since the weak precipitate spots generally do not appear on the diffraction patterns.

scholarly journals On the Nature of R 136, the Central Object of 30 Dor. A Comparison by the Galactic Cluster NGC 3603

1984 ◽  
Vol 108 ◽  
pp. 257-258
Author(s):  
Michael Rosa ◽  
Jorge Melnick ◽  
Preben Grosbol
Keyword(s):  
Core Region ◽  
H Ii Regions ◽  
Central Object ◽  
The Core ◽  
Dominant Component ◽  
Galactic Cluster ◽  
H Ii Region

The massive H II region NGC 3603 is the closest galactic counterpart to the giant LMC nebula 30 Dor. Walborn (1973) first compared the ionizing OB/WR clusters of the two H II regions and suggested that R 136, the unresolved luminous WR + 0 type central object of 30 Dor, might be a multiple system like the core region of NGC 3603. Suggestions that the dominant component of R 136, i.e. R 136A, might be either a single or a very few supermassive and superluminous stars (Schmidt-Kaler and Feitzinger 1982, Savage et al. 1983) have recently been disputed by Moffat and Seggewiss (1983) and Melnick (1983), who have presented spectroscopic and photometric evidence to support the hypothesis of an unresolved cluster of stars. We have extended Walborn's original comparison of the apparent morphology of the two clusters by digital treatment of the images to simulate how the galactic cluster would look like if it were located in the LMC

Optical Temperature Sensing of Core-Shell Structured NaYF4:Yb3+, Er3+@NaYF4 Nanocrystals with Different Shell Thickness

2015 ◽  
Vol 738-739 ◽  
pp. 27-30
Author(s):  
Dong Dong Li ◽  
Qi Yue Shao ◽  
Yan Dong ◽  
Jian Qing Jiang
Keyword(s):  
Shell Thickness ◽  
Thermal Sensitivity ◽  
Upconversion Luminescence ◽  
Temperature Sensing ◽  
Upconversion Nanoparticles ◽  
Core Shell ◽  
Sensing Properties ◽  
The Core ◽  
Β Phase ◽  
Biomedical Fields

Hexagonal (β)-phase NaYF4:Yb3+, Er3+ upconversion nanoparticles (UCNPs) with and without an inert (undoped NaYF4) shell have been successfully synthesized and the effects of shell thickness on the upconversion luminescence (UCL) and temperature sensing properties were systematically investigated. It was found that the NaYF4 shell and its thickness do not affect the RHS values and thermal sensitivity, but can obviously improve the UCL intensity of NaYF4:Yb3+, Er3+ UCNPs. It implies that the core-shell structured NaYF4:Yb3+, Er3+@NaYF4 UCNPs with excellent UCL properties have great potential to be used as temperature sensing probes in biomedical fields, without considering the influences of the shell thickness on their temperature sensing properties.

Sign in / Sign up

Export Citation Format

Share Document