Study of the behaviour of AlZn alloys by SAXS in the temperature range of the instable solid solution

1983 ◽  
Vol 78 (2) ◽  
pp. 497-506 ◽  
Author(s):  
G. Wendrock
Author(s):  
Takashi Yamamoto ◽  
Akihito Kurimoto ◽  
Riona Sato ◽  
Shoki Katada ◽  
Hirotaka Mine ◽  
...  

Ethanol conversion by Ga2O3-ZrO2 solid solution was examined in the temperature range 573–773 K, and acetone/isobutene formation was confirmed under cofeeding of H2O vapor. The reaction pathway was empirically investigated...


2002 ◽  
Vol 110 (1286) ◽  
pp. 899-903 ◽  
Author(s):  
Tsuyoshi SASAKI ◽  
Yoshio UKYO ◽  
Akihiko SUDA ◽  
Masahiro SUGIURA ◽  
Kotaro KURODA ◽  
...  

Author(s):  
А.А. Семакова ◽  
В.В. Романов ◽  
Н.Л. Баженов ◽  
К.Д. Мынбаев ◽  
К.Д. Моисеев

The results of a study of the electroluminescence of the asymmetric InAs/InAs1−ySby/InAsSbP LED heterostructures with a molar fraction of InSb in the ternary solid solution in the active region y=0.15 and y=0.16 in the temperature range 4.2−300 K are presented. Based on the experimental data, the formation of a staggered type II heterojunction at the InAs1−ySby/InAsSbP heterointerface was determined. The dominant contribution of the interface radiative transitions at the type II heterointerface in the temperature range 4.2−180 K was shown, which makes it possible to minimize the temperature dependence of the operating wavelength of the LEDs.


2008 ◽  
Vol 368-372 ◽  
pp. 1879-1882 ◽  
Author(s):  
Kenichi Kakimoto

Nb-based systems have been considered to be the most attractive ceramic system in the research field of lead-free piezoceramics, since excellent piezoelectric properties were reported in (Li,Na,K)NbO3-based solid solution (LNKN) systems. This article reviews the characteristic and recent research activity for several kinds of the niobate systems including LiNbO3, NaNbO3, KNbO3, tungsten-bronze niobate. The importance of material design for enhancement of piezoelectric properties and their stability in the wide temperature range is also described for LNKN system.


2012 ◽  
Vol 322 ◽  
pp. 33-39 ◽  
Author(s):  
Sergei Zhevnenko ◽  
Eugene Gershman

High-temperature creep experiments were performed on a Cu-2.8 ат.% Co solid solution. Cylindrical foils of 18 micrometers thickness were used for this purpose. Creep tests were performed in a hydrogen atmosphere in the temperature range of about from 1233 K to 1343 K and at stresses lower than 0.25 MPa. For comparison, a foil of pure copper and Cu-20 at.% Ni solid solution were investigated on high temperature creep. Measurements on the Cu foil showed classical diffusional creep behavior. The activation energy of creep was defined and turned out to be equal 203 kJ/mol, which is close to the activation energy of bulk self-diffusion of copper. There was a significant increase in activation energy for the Cu-20 at.% Ni solid solution. Its activation energy was about 273 kJ/mol. The creep behavior of Cu-Co solid solution was more complicated. There were two stages of diffusional creep at different temperatures. The extremely large activation energy (about 480 kJ/mol) was determined at relatively low temperature and a small activation energy (about 105 kJ/mol) was found at high temperatures. The creep rate of Cu-Co solid solution was lower than that of pure copper at all temperatures. In addition, the free surface tension of Cu-2.8 ат.% Co was measured at different temperatures from 1242 K to 1352 K. The surface tension increases in this temperature range from 1.6 N/m to 1.75 N/m. There were no features on the temperature dependence of the surface tension.


2011 ◽  
Vol 176 ◽  
pp. 107-118 ◽  
Author(s):  
Janusz Adamiec

This work, in combination with industrial tests of casting welding, shows that the causes of high-temperature brittleness are the partial tears of the structure and the hot cracks of both the castings, as well as the welded and padded joints. Such phenomena should be treated as irreversible failures caused by the process of crystallization that is in the area of co-existence of the solid and liquid structural constituent. Nil-strength temperature (NST), nil-ductility temperature (NDT) and ductility recovery temperature (DRT) were determined using Gleeble 3800. Obtained results enabled the defining of brittle temperature range of MSR-B magnesium alloy. The assessment of the resistance to hot fractures was conducted on the basis of the transvarestriant trial. The transvarestriant trial involves changing of strain during welding. It was stated that the range of the high-temperature brittleness is very broad, which significantly limits the application of the welding techniques to join or repair elements made of the MSRB alloy. brittleness is caused mainly by metallurgical factors, i.e. precipitation of intermetallic phases from the solid solution.


1979 ◽  
Vol 101 (2) ◽  
pp. 331-334 ◽  
Author(s):  
M. N. O¨zis¸ik ◽  
J. C. Uzzell

The problem of solidification by a line heat sink in an infinite medium with cylindrical symmetry for a substance having an extended freezing temperature range between the solidus and liquidus temperatures is solved exactly for two different cases characterizing the distribution of the solid fraction within the two-phase zone. In one of the models, the solid fraction is assumed to vary linearly with the temperature and in the other solidification within the two-phase zone is assumed to have a linear relationship with the distance. The analysis is applicable for both eutectic and solid solution alloys.


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