Heat of interaction of oxygen with dysprosium and yttrium

1988 ◽  
Vol 53 (10) ◽  
pp. 2412-2417 ◽  
Author(s):  
Slavoj Černý ◽  
Milan Kovář
Keyword(s):  
Solid Solution ◽  
Rare Earth ◽  
Sorption Capacity ◽  
Room Temperature ◽  
Rare Earth Metals ◽  
High Reactivity ◽  
Oxygen Species ◽  
Low Oxygen ◽  
Metal Ratio ◽  
Metal Ratios

Heat of interaction of oxygen dosed to vacuum-evaporated films of dysprosium and yttrium were measured in a calorimeter at room temperature. The high and rapidly produced heat, and the attained oxygen-to-metal ratio indicate high reactivity of these rare earth metals towards oxygen molecules which obviously undergo dissociative sorption. The energy of bonding of the formed oxygen species to the metal was estimated to 723 kJ/mol (173 kcal/mol) and 780 kJ/mol (186 kcal/mol) for Dy and Y, respectively. A markedly higher sorption capacity of Y film compared to Dy film was observed. The heat produced by the first admitted doses of oxygen may suggest formation of a solid solution of oxygen species in Dy and Y at very low oxygen-to-metal ratios.

scholarly journals Effect of Al-Y-Ce-La master alloy on structure formation, liquation processes and properties of AK7ch silumine (AL9)

2019 ◽  
Vol 298 ◽  
pp. 00056
Author(s):  
Ernst Kh. Ri ◽  
Khosen Ri ◽  
Aleksei V. Goncharov
Keyword(s):  
Solid Solution ◽  
Rare Earth ◽  
Structure Formation ◽  
Master Alloy ◽  
Rare Earth Metals ◽  
Variable Composition ◽  
Sharp Change ◽  
Structural Components

The regularities of changes in the composition and properties (micro- and nanohardness, HB hardness) of the structural components - α-solid solution and eutectic components of the AK7ch alloy (AL9) depending on the value of the addition of Al-Y-Ce-La master alloy are established. With an increase in the addition of Al-Y-Ce-La master alloy a sharp change is observed in the composition and properties of the structural components of the AK7ch alloy - α-solid solution Si in aluminum and eutectic α + Si, as well as complex-doped aluminides from Si, Fe and rear earth metals (REM). The structural components of the AK7ch alloy are identified with the addition of an increasing amount of Al-Y-Ce-La master alloy (α-solid solution of Si in aluminum, eutectic α+Si, complex-doped aluminides of rare-earth metals of variable composition AlxSiyREMz and AlxSiyFezREMν). A correlation between the solubility of silicon in α-solid solution and its microhardness is found. To increase microhardness of the eutectic and hardness of the AK7ch alloy, it is necessary to add the synthesized ligature in the amount of 0.1 wt.%.

Microstructures and Mechanical Properties of AJ62 Magnesium Alloy with Y and Nd Elements

2011 ◽  
Vol 686 ◽  
pp. 253-259
Author(s):  
Xu Ning ◽  
Wei Dong Xie ◽  
Chun Mei Dang ◽  
Xiao Dong Peng ◽  
Yan Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Tensile Strength ◽  
Rare Earth ◽  
Magnesium Alloy ◽  
Room Temperature ◽  
Solution Treatment ◽  
Solid Solution Treatment ◽  
Microstructure And Mechanical Properties ◽  
Microstructures And Mechanical Properties

A series of Mg-6Al-2Sr-1.5Y-xNd (x=0, 0.3, 0.6, 0.9, 1.2) alloy samples were prepared and their microstructures were observed and mechanical properties were measured. The existing forms of Y and Nd were studied. The effects of Y and Nd on microstructure and mechanical properties of AJ62 alloy were investigated. The results show that the main existing forms of Y and Nd in AJ62 alloy are Al2Y and Al2Nd. The combined addition of rare earth Y and Nd can refine α-Mg matrix obviously and reduce the amount of the β-Mg17Al12phases; after solid solution treatment, the tensile strength of the alloys rise first and fall later with increasing content of Nd. When the content of Nd is about 0.6%wt, the values of tensile strengthes are up to the maximum both at room temperature and at 448 K.

Phenomenon of reversion after ageing in magnesium alloys with gadolinium and samarium

2020 ◽  
Vol 12 ◽  
pp. 16-26
Author(s):  
L. L. Rokhlin ◽  
◽  
T. V. Dobatkina ◽  
N. Yu. Tabachkova ◽  
I. E. Tarytina ◽  
...  
Keyword(s):  
Solid Solution ◽  
Rare Earth ◽  
Magnesium Alloys ◽  
Electrical Resistance ◽  
Annealing Temperature ◽  
Rare Earth Metals ◽  
Base Solid Solution ◽  
Short Annealing ◽  
Cerium Group ◽  
The Rare Earth

The parameters of reversion after hardening ageing of magnesium alloys containing two rare-earth metals: gadolinium (yttrium group) and samarium (cerium group) were determined at various ratios of their contents. The reversion was observed at short annealing at 250 and 300 °С beginning with 5 minutes after preliminary ageing at 200 °С up to maximum hardening and consisted of significant softening of the alloys then. Measurements of the electrical resistance indicated, that during softening the reverse dissolution of the rare-earth metals in magnesium-base solid solution takes place with diminution of the hardening particles quantity, precipitated during ageing before The reverse dissolution of the rare-earth metals into solid magnesium increases with elevating annealing temperature after ageing from 250 to 300 °С and with increase of the gadolinium to samarium ratio in the alloys.

scholarly journals PRELIMINARY STUDY ON SEPARATION OF RARE EARTH METALS FROM LEACH SOLUTION OF DISCARDED FLUORESCENT POWDER BY SOLVENT EXTRACTION

2018 ◽  
Vol 56 (2C) ◽  
pp. 133-139
Author(s):  
Nguyen Duc Quang
Keyword(s):  
Rare Earth ◽  
Solvent Extraction ◽  
Room Temperature ◽  
Rare Earth Metals ◽  
Leach Solution ◽  
Extractant Concentration ◽  
Fluorescent Lamps ◽  
Fluorescent Powder ◽  
Acid Leach ◽  
Counter Current

Discarded fluorescent lamps were considered as hazardous waste in Vietnam (code is 160106). However, its composition contained valuable rare earth metals, which can be recycled and recovered by leaching and solvent extraction processes. The present study sought to define the conditions of separation for rare earth elementals (REEs) from acid leach solution by solvent extraction using PC88A. The acid leach solution was obtained from leaching of fluorescent powder. Efficiencies on REEs extractions as functions of pH levels, extractant concentration, O/A ratio, metal concentration were investigated. For pH values greater than 0.0 and less than 1.0, the orders of the yields extraction were determined: yttrium > terbium > europium > aluminum and calcium. The best separation circuit included four-stage counter current extraction for yttrium separation with 20 %v/v PC88A in kerosene (O/A = 1/1, room temperature, 20 min of contact, pH of 0.38) and stripping step with 3 M HCl acid (O/A = 1/1, room temperature, 30 min of contact). After yttrium separation, the leach solution was extracted at pH of 0.98 in the same other conditions with two-stage counter current extraction to recover terbium and europium group. The final recovery from leach liquor was higher than 98 % and the grade of the final product was 94.2 % (for yttrium) and 93.8 % (for terbium and europium group).

Magnetic susceptibility of liquid heavy rare earth metals

1979 ◽  
Vol 40 (C5) ◽  
pp. C5-260-C5-261 ◽  
Author(s):  
M. Müller ◽  
E. Huber ◽  
H.-J. Güntherodt
Keyword(s):  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Rare Earth Metals ◽  
Heavy Rare Earth

ELECTRONIC RELAXATION IN RARE EARTH METALS AND ALLOYS - A NON-KRAMERS EXAMPLE : Tm3+

1980 ◽  
Vol 41 (C1) ◽  
pp. C1-25-C1-31 ◽  
Author(s):  
N. S. Dixon ◽  
L. S. Fritz ◽  
Y. Mahmud ◽  
B. B. Triplett ◽  
S. S. Hanna ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Metals And Alloys ◽  
Electronic Relaxation
Sign in / Sign up

Export Citation Format

Share Document