X-ray study of AlSi 7 alloy cast in sand mold using an ultrasound field

2008 ◽  
Vol 39 (2) ◽  
pp. 198-200
Author(s):  
E. R. Mihoc ◽  
D.D. Porcar ◽  
I. Porcar
Keyword(s):  
Sand Mold ◽  
X Ray ◽  
Ultrasound Field ◽  
Alloy Cast

scholarly journals The Relationship between Residual Amount of Sr and Morphology of Eutectic Si Phase in A356 Alloy

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3222 ◽  
Author(s):  
Wenda Zhang ◽  
Shixuan Ma ◽  
Zhenhua Wei ◽  
Peikang Bai
Keyword(s):  
A356 Alloy ◽  
Sand Mold ◽  
Sr Modification ◽  
Treatment Processes ◽  
Modification Effect ◽  
Residual Amount ◽  
Eutectic Si ◽  
The Relationship ◽  
Modification Treatment ◽  
Alloy Cast

This paper studied the relationship between the residual amount of Sr and the morphology of the eutectic Si phase in A356 obtained through different modification treatment processes; additionally, the cooling rates of molds were studied. The eutectic Si phase revealed a satisfactory modification effect at residual Sr amounts above 0.01 wt % in A356 alloys cast using an iron mould. Complete modification of the eutectic Si phase could be achieved at a Sr additive amount 0.03 wt % in an A356 melt. The addition of higher amounts of Sr (~0.04–0.06 wt %) did not improve the modification effect. With the addition of 0.06 wt % Sr into A356 alloy melt and holding at 750 °C, the anti-fading capacity of Sr modification effect could be sustained for 120 minutes. More Sr is needed to obtain a good modification of eutectic Si for an A356 alloy cast using a sand mold.

Study the Effect of HAp Content in PLA/HAp Microsphere on the Efficiency of Drug (Clindamycin) Loading Process

2013 ◽  
Vol 834-836 ◽  
pp. 559-562 ◽  
Author(s):  
Juntima Pradid ◽  
Wirunya Keawwattana ◽  
Siree Tangbunsuk
Keyword(s):  
Electron Microscopy ◽  
Thermal Process ◽  
High Performance ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultrasound Field ◽  
Sample Characterization ◽  
Core Shell Structure ◽  
Scanning Electron

An ultrasound field was applied to obtain Polylactic acid (PLA)/Hydroxyapatite (HAp) biocomposite microspheres with the specific core-shell structure to be applied as a carrier of a drug. The hydroxyapatite was obtained from crocodile bone by thermal process. Sample characterization was achieved by powder X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX) Scanning electron microscopy (SEM) and High Performance Liquid Chromatography (HPLC). As the result, the PLA/HAp loading clindamycin with different polymer-to-ceramic part wt.% ratio (100:0, 90:10, 80:20, and 70:30) showed the agglomeration of sphere-like particles. In addition, the loading efficiency of clindamycin increased with increasing HAp content up to 20%.

scholarly journals Evaluation of nano ceramic coating on radiographic defects of thin-walled AL4-4 aluminum alloy sand casting

10.30544/212 ◽  
2016 ◽  
Vol 22 (3) ◽  
pp. 193-204
Author(s):  
Mansour Borouni ◽  
Behzad Niroumand ◽  
Mohammad Hossein Fathi
Keyword(s):  
Transfer Rate ◽  
Ceramic Coating ◽  
Maximum Amount ◽  
Sand Mold ◽  
Gravity Casting ◽  
X Ray ◽  
Ceramic Nanoparticles ◽  
Shrinkage Defects ◽  
Thin Walled

Internal defects are among the problems in gravity casting of aluminum parts. The main internal volumetric defects are gas and shrinkage defects which form during solidification of the melt and drastically reduce the quality of the produced parts. These defects adversely affect the mechanical properties of thin walled castings parts. In this study, ceramic nanoparticles coatings were applied on the sand mold and the effect of mold coatings on the reduction of defects were investigated. X-ray radiography was used to detect defects in sand molds with ceramic nanoparticles coatings. For comparison, this test was performed on molds with micro-ceramic and graffiti coatings and uncoated sand mold. The results showed that the maximum amount of gas and shrinkage defects was observed in casting parts from AL4-1 alloy in uncoated molds. On the other hand, the minimum defects were found in molds coated with ceramic nanoparticles. It seems that the reduced defects in casting parts in molds coated with ceramic nanoparticles may be due to high thermal and chemical stability and higher heat transfer rate of the coating. These results can facilitate the production of high quality aluminum alloys parts using nanotechnology.

scholarly journals Study of the evolution of transport properties induced by additive processing sand mold using X-ray computed tomography

2020 ◽  
Vol 277 ◽  
pp. 116495
Author(s):  
Saptarshee Mitra ◽  
Mohamed EL Mansori ◽  
Antonio Rodríguez de Castro ◽  
Marius Costin
Keyword(s):  
Computed Tomography ◽  
Transport Properties ◽  
Sand Mold ◽  
X Ray ◽  
X Ray Computed

Microstructure and elevated temperature mechanical properties of Mg-6Gd-3Y-0.5Zr alloy cast by PEP–SET sand mold

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Y. J. Huang ◽  
Y. F. Wang ◽  
S. Y. Zhang ◽  
G. L. Zhang ◽  
F. Y. Cao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phenolic Resin ◽  
Elevated Temperatures ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Microstructural Characterization ◽  
Sand Mold ◽  
Pressure Casting ◽  
Alloy Component ◽  
Alloy Cast

Abstract The present work cast a complex Mg-6Gd-3Y-0.5Zr alloy component in a polybenzylic ether phenolic resin (PEP-SET) sand mold using by differential pressure casting. Microstructural characterization was carried out on the castings in the states of as-cast, solution treatment and aging treatment. Their mechanical properties were examined at elevated temperatures. The studied Mg alloy showed noticeably high tensile strengths up to 473 K, followed by a significant decrease with further increasing the testing temperatures. Its mechanical properties at elevated temperatures were compared with those of WE43 alloy fabricated under identical casting conditions.

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Iron K-Line Emission from X-Ray Binaries

1988 ◽  
Vol 102 ◽  
pp. 47-50
Author(s):  
K. Masai ◽  
S. Hayakawa ◽  
F. Nagase
Keyword(s):  
Accretion Disk ◽  
Radiative Recombination ◽  
Characteristic Temperature ◽  
Line Emission ◽  
Ionization Front ◽  
Continuum Radiation ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx> 10 keV is likely due to fluorescence outside the He II ionization front.

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