scholarly journals Impact of the Solidification Rate on the Chemical Composition of Frozen Cryolite Bath

Metals ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 97 ◽  
Author(s):  
Sándor Poncsák ◽  
László Kiss ◽  
Sébastien Guérard ◽  
Jean-François Bilodeau
Keyword(s):  
Chemical Composition ◽  
Solidification Rate ◽  
Cryolite Bath

The Effect of Thermal Treatment on the Microstructural Evolution of an Al-Cu Alloy

2003 ◽  
Author(s):  
Tracie L. Zoeller ◽  
Thomas H. Sanders
Keyword(s):  
Aluminum Alloy ◽  
Chemical Composition ◽  
Marked Effect ◽  
Volume Fraction ◽  
Solidification Rate ◽  
Thermal Treatments ◽  
Large Volume Fraction ◽  
Cu Alloy ◽  
Processing Step ◽  
Alloy Microstructure

Following solidification, an aluminum alloy microstructure is highly segregated. The microstructure consists of cored dendrites with various soluble and insoluble phases present in the dendritic regions. The solidification rate has a marked effect on the amount of coring that an alloy experiences. Understanding the effects of the solidification rate is important in explaining differences in microstructures. Subsequent heat treatments are performed to homogenize the microstructure. The microstructure evolution after each processing step is dependent upon the previous microstructures. The variation in local chemical composition may promote or hinder precipitation of new phases. A large volume fraction of coarse insoluble phases can lead to the occurrence of recrystallized grains via particle stimulated nucleation, while inhomogeneous solute distribution can lead to the precipitation of an uneven distribution of dispersoid phases. The effect of solidification rate and subsequent thermal treatments on the microstructure of an Al-4Cu alloy will be investigated and experimental and numerical results will be presented.

scholarly journals Quantitative characterization of mns inclusions in S355 steel regarding to solidification rate

2013 ◽  
Vol 67 (2) ◽  
pp. 331-336
Author(s):  
Aida Mahmutovic
Keyword(s):  
Chemical Composition ◽  
Special Interest ◽  
Electron Probe ◽  
Solidification Rate ◽  
Equilibrium Phase ◽  
Casting Surface ◽  
Electron Probe Microanalyzer ◽  
Metallic Inclusions ◽  
Thermo Calc Software ◽  
Liquidus Temperatures

A practice of special interest for metallurgical steelmaking is the relationship between redistribution of solute elements and dendrite microsegregation that occurs during solidification. These phenomena have a significant impact on the final properties of cast and forged products. In this paper, a calculation of the characteristic chemical phases in S355 steel using a software program Thermo-Calc is presented. Also, the paper presents experimental measurements of the dendrites size and non-metallic inclusions using optical and electron probe microanalyzer, as well as the calculation of the local solidification rate on the particular example. These phenomena are of special interest when it comes to thin castings and higher cooling rates. Thin castings require higher quality of casting surface, corresponding distribution, and character than those of non-metallic inclusions. Thermo-calc software was used for calculation of equilibrium phases, temperature ranges of solidification of tested material, and temperature range for developing characteristic equilibrium phase. It was found that during solidification and cooling processes manganese sulphide inclusions were formed. Additionally, accurate values for solidus and liquidus temperatures, which coincide with the values of solidus and liquidus temperatures obtained by the Thermo Calc, were calculated. Using optical and electron probe microanalyzer, the type of inclusions were confirmed, whereas chemical composition and size measurement of dendrites, and formed non-metallic inclusions were determined. Mapping and Linescan methods were used to examine the size and exact chemical composition of sulphides in atomic percents. Using secondary dendrites local solidification rate was calculated (for casting surface area solidification rate was 5 K/s). This paper gives contribution to better understanding the influence of cooling rate on casting microstructure formation and dendrites, which essentially determine the size of non-metallic inclusions and their redistribution.

scholarly journals Influence of Chemical Composition and Solidification Rate on the Abrasion and Impact Properties of CADI

2009 ◽  
Vol 49 (8) ◽  
pp. 1239-1245 ◽  
Author(s):  
Sebastián Laino ◽  
Jorge A. Sikora ◽  
Ricardo C. Dommarco
Keyword(s):  
Chemical Composition ◽  
Solidification Rate ◽  
Impact Properties

The Modified AlSi7Mg0.3 Cast Alloy Mechanical Properties Changes at Different Testing Temperatures

2014 ◽  
Vol 635 ◽  
pp. 13-17
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Chemical Composition ◽  
Thermal Treatment ◽  
Cast Alloy ◽  
Solidification Rate ◽  
Casting Process ◽  
Melt Treatment ◽  
Treatment Conditions ◽  
Higher Temperature

The Al-Si cast alloy mechanical properties and microstructure depends on the chemical composition; melt treatment conditions, solidification rate, casting process and the applied thermal treatment. Modification can be achieved by several methods as faster solidification, mould vibration, and melt inoculation by using chosen elements like Sr, Na, Sb, etc. Present work is focused on study of the effect of Sb-modification (with AlSb10 from 0 up to 300 ppm) on the structure and mechanical properties in AlSi7Mg0.3 cast alloy. AlSi7Mg0.3 alloy can be used for high temperature casting (e.g. engine, pistons) therefore is necessary to determine the properties at higher temperature. The mechanical properties were evaluated at room (21 °C) and 260 °C. The results show that the modification of experimental material is important. Experimental alloy has by optimal modification (50 ppm Sb) UTS at 260 °C above 100 MPa.

Effects of the Casting Temperature in the Leakage of Zamak 5

2017 ◽  
Vol 899 ◽  
pp. 458-462 ◽  
Author(s):  
Patrícia Marcolin ◽  
Marielen Longhi ◽  
Lucas Pandolphi Zini ◽  
Sandra Raquel Kunst ◽  
Ademir José Zattera ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Open Circuit Potential ◽  
Solidification Rate ◽  
Open Circuit ◽  
Casting Temperature ◽  
Injection Process ◽  
Different Temperatures ◽  
Porosity Defects ◽  
Solidification Defects ◽  
Electrochemical Analyses

Recent studies evidenced that the Zamak 5 corrosion is associated to solidification defects arising from the injection process that occur mainly in areas where the solidification rate is faster. Given this factor, the aim of this research was to evaluate the influence of Zamak 5 casting temperature. For this study, Zamak 5 was casted at different temperatures (430 °C, 450 °C, 500 °C, 550 °C) with respective solidification curves. Zamak 5 was analyzed for chemical composition and microstructure. Moreover, complementary tests of microhardness and electrochemical analyses of open circuit potential and polarization were performed. From these analyses it was observed that the highest casting temperature of Zamak 5 originates larger grains and higher microhardness value, due to the lower solidification rate. In none of the leaking temperatures porosity defects were observed on the samples, which is coherent with previous researches, being originated from the injection process.

Texture in NiTi-Based Shape Memory Alloys Produced by Twin Roll Casting

2013 ◽  
Vol 203-204 ◽  
pp. 101-104 ◽  
Author(s):  
Tomasz Goryczka ◽  
Patrick Ochin
Keyword(s):  
Chemical Composition ◽  
Heat Flow ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Cross Section ◽  
Solidification Rate ◽  
Casting Technique ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

Two shape memory alloys with nominal chemical composition: Ni50Ti50 and Ni47Ti50Co3 were produced using twin roll casting technique (TRC). Relatively high cooling rate realized during solidification causes directional heat flow. In result of that, high textured strips were produced. However, the total amount of the preferentially oriented grains differs between surface and cross-section of the strip. At surface, where the crystallization of the grains is the most intensive amount of the grains can reach about 77%. At the cross-section of both strips, where the solidification rate decreased, the total amount of the textured grains was not higher than 57%.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

On the Inhomogeneity of Chemical Composition over the Surface of 21 Per

1976 ◽  
Vol 32 ◽  
pp. 343-349
Author(s):  
Yu.V. Glagolevsky ◽  
K.I. Kozlova ◽  
V.S. Lebedev ◽  
N.S. Polosukhina
Keyword(s):  
Chemical Composition ◽  
Spectral Line ◽  
Variable Star ◽  
Radial Velocities ◽  
Crimean Astrophysical Observatory ◽  
Line Intensities ◽  
Magnetic Variable

SummaryThe magnetic variable star 21 Per has been studied from 4 and 8 Å/mm spectra obtained with the 2.6 - meter reflector of the Crimean Astrophysical Observatory. Spectral line intensities (Wλ) and radial velocities (Vr) have been measured.

Structural Studies on Mitotic Spindle Fibres

1978 ◽  
Vol 36 (3) ◽  
pp. 615-626
Author(s):  
J.R. Mcintosh
Keyword(s):  
Chemical Composition ◽  
Mitotic Spindle ◽  
Structural Studies ◽  
Mitotic Apparatus ◽  
Chemical Studies ◽  
Medical Interest ◽  
Spindle Fibres

The mitotic apparatus is a structure of obvious biological and medical interest, but it has proved to be a difficult cellular machine to understand. The chemical composition of the spindle is only slightly elucidated, largely because of the difficulties in preparing useful isolates of the structure. Chemical studies of the mitotic spindle have been reviewed elsewhere (Mcintosh, 1977), and will not be discussed further here. One would think that structural studies on the mitotic apparatus (MA) in situ would be straightforward, but even with this approach there is some disagreement in the results obtained with various methods and by different investigators. In this paper I will review briefly the approaches which have been used in structural studies of the MA, pointing out the strengths and problems of each approach. I will summarize the principal findings of the different methods, and identify what seem to be fruitful avenues for further work.

Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

1971 ◽  
Vol 29 ◽  
pp. 570-571
Author(s):  
E. A. Elfont ◽  
R. B. Tobin ◽  
D. G. Colton ◽  
M. A. Mehlman
Keyword(s):  
Chemical Composition ◽  
Rat Liver ◽  
Future Study ◽  
Mode Of Action ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Effective Inhibitor ◽  
Biochemical Effects ◽  
Glycerophosphate Dehydrogenase ◽  
Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

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