Recrystallisation of Magnesium Alloys Containing Rare-Earth Elements

2013 ◽  
Vol 753 ◽  
pp. 297-300 ◽  
Author(s):  
Nicole Stanford
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Magnesium Alloys ◽  
Hot Rolling ◽  
Earth Element ◽  
Rare Earth Alloy ◽  
Annealing Temperatures ◽  
High Annealing ◽  
Conventional Alloy ◽  
The Rare Earth

The static recrystallisation behaviour of two magnesium alloys after hot rolling have been examined. The alloys chosen for study were the conventional alloy AZ31, and an alloy containing the rare earth element Gadolinium. The recrystallisation kinetics were lower for the rare-earth alloy at low annealing temperatures, but at high annealing temperatures the kinetics were higher for the rare-earth alloy. It is suggested that this change in the comparative recrystallisation kinetics is a result of the improved mobility of the rare-earth solute at higher temperatures. This affects the recrystallisation kinetics through solute partitioning to the grain boundaries. The effect of this segregation on the recrystallisation texture is also discussed.

Study on Recovery of Rare Earth Elements from NdFeB Magnet Scrap by Using Selective Leaching

2020 ◽  
Vol 1009 ◽  
pp. 149-154
Author(s):  
Tanongsak Yingnakorn ◽  
Piamsak Laokhen ◽  
Loeslakkhana Sriklang ◽  
Tapany Patcharawit ◽  
Sakhob Khumkoa
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earth Element ◽  
Earth Element ◽  
Rare Earth Metals ◽  
Hard Disk Drives ◽  
Selective Leaching ◽  
High Concentration ◽  
Neodymium Magnets ◽  
The Rare Earth

High power neodymium magnets have been used extensively, such as components of hard disk drives, electric vehicles, and maglev trains. This type of magnet contains of high concentration of rare earth elements. After the device is out of service, the magnet will be removed and the rare earth element contained in the magnet will be extracted in order to reuse for any purposes. Recently, the study on extraction of rare earth elements (REE) from neodymium magnets is increased. However, there was only few research regarding to the extraction of rare earth metals by using a water leaching method. In this study, rare-earth elements were extracted from neodymium magnet scrap by using selective leaching technique. Initially, magnets were leached with 2 M of sulfuric acid for 24 hrs. Then, the leached solution was heated at 110°C in order to remove water and the green powder was remained. The green powder was further roasted in a muffle furnace at various temperatures from 750°C to 900°C for 2 hrs. and subsequently leached by water. Finally, the iron oxide residue was separated from rare earth element solution by filtration. Based on this experiment, it was found that the purity of the rare earth metals can be achieved up to 99.4%.

Foliar application of rare earth elements to maize and mungbean

1999 ◽  
Vol 39 (2) ◽  
pp. 189 ◽  
Author(s):  
E. Diatloff ◽  
C. J. Asher ◽  
F. W. Smith
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earth Element ◽  
Earth Element ◽  
Foliar Application ◽  
Dry Weight ◽  
Cerium Nitrate ◽  
Beneficial Effects ◽  
Shoot Dry Weight ◽  
The Rare Earth

The foliar application of rare earth elements to plants has been reported to increase yields of a range of crops particularly when soils contain low levels of rare earth elements. A rare earth element fertiliser obtained from China was chemically analysed and found to contain 45.3% nitrate plus 8.7% lanthanum and 12.4% cerium; lanthanum and cerium were the most abundant rare earth elements measured. This fertiliser was applied once, as 0, 0.025, 0.05, 0.1, 0.5 and 1.0% (w/v) aqueous solutions to the foliage of 10-day-old maize (Zea mays L. cv. Hycorn 82) and 14-day-old mungbean [Vigna radiata (L.) Wilczek cv. Berken] plants grown in a nutrient-rich potting mix of low total rare earth element status. For comparison, a duplicate set of plants was sprayed with solutions containing analytical grade lanthanum and cerium nitrate at concentrations equivalent to those measured in the rare earth element fertiliser. No beneficial effects of the rare earth element treatments were observed. The shoots of maize and mungbean sprayed with ≤0.1% rare earth element fertiliser or equivalent appeared completely healthy throughout the experiment, but plants in the 0.5 and 1.0% treatments showed symptoms of leaf burn in maize, and small necrotic spots on mungbean leaves within 1–3 days of treatment. These symptoms became more severe over the next 5–9 days. The shoot dry weight of mungbean sprayed with 0.5 and 1.0% solutions was significantly (P<0.05) reduced by 27%. Symptoms observed on plants sprayed with lanthanum and cerium nitrate solutions were similar to those observed on plants sprayed with the rare earth element fertiliser, and similar growth reductions occurred also.

The Application of Rare-Earth Element

2011 ◽  
Vol 233-235 ◽  
pp. 3005-3009
Author(s):  
Yu Cai Wu ◽  
Ming Yan
Keyword(s):  
Tensile Strength ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earth Element ◽  
Earth Element ◽  
Additive Process ◽  
Contact Wire ◽  
Specific Elongation ◽  
Ag Contact ◽  
The Rare Earth

In this paper, the process of Cu-Ag contact wire with adding rare-earth elements was presented. The additive process of the rare-earth elements and the function of the rare earth were chiefly analyzed. Adding the rare-earth elements into melt alloy, the oxide and sulfur can be removed from the liquid, so we can get the purified alloy. At the same time, adding rare-earth can reduce the external crack flaws which produced during the casting and makes the grain refined, as the result, the properties of the Cu-Ag alloy contact wire can be greatly improved and meliorated. Such as the conductivity, the specific elongation, tensile strength and so on, are improved.

Effect of Rare Earth Elements on the Inclusion Behavior in Low Alloy Structural Steel

2019 ◽  
Vol 944 ◽  
pp. 364-372
Author(s):  
Na Yin ◽  
Cai Liang Jing ◽  
Hai Bo Li ◽  
Ren Sheng Chu ◽  
Bin Chen
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Structural Steel ◽  
Earth Element ◽  
Steel Production ◽  
Obvious Effect ◽  
Furnace Process ◽  
Rare Earth La ◽  
Refining Processes ◽  
The Rare Earth

In this paper, the effect of rare earth elements on the behavior of inclusions for low-alloy structural steel production was studied. The results showed that adding rare earth elements after different refining processes had a great impact on the results: (1) When adding rare earth elements after the LF furnace process, the alloy yield was low, and the rare earth inclusions was rare, the pure and coexisted inclusions of rare earth (La & Ce) were found; (2) While added after the RH furnace process, the alloy yield and the amount of rare earth inclusions increased greatly, but only coexisted inclusions of rare earth (La & Ce) were found. Furthermore, the precipitates of Nb and the contents of Al and Mg in the inclusions were also sharply reduced, which indicated that the rare earth element had obvious effect on the denaturation of the inclusions.

Geochemistry of the rare-earth elements in hypersaline and dilute acidic natural terrestrial waters: Complexation behavior and middle rare-earth element enrichments

1996 ◽  
Vol 133 (1-4) ◽  
pp. 125-144 ◽  
Author(s):  
Kevin H. Johannesson ◽  
W.Berry Lyons ◽  
Mary A. Yelken ◽  
Henri E. Gaudette ◽  
Klaus J. Stetzenbach
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earth Element ◽  
Earth Element ◽  
The Rare Earth

The Stannides RE2Ni2Sn (RE = Pr, Ho, Er, Tm) – Structural Transition from the W2B2Co to the Mo2B2Fe Type as a Function of the Rare Earth Size

2013 ◽  
Vol 68 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Birgit Heying ◽  
Ute Ch. Rodewald ◽  
Bernard Chevalier
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Earth Element ◽  
Structural Transition ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Arc Melting ◽  
The Rare Earth

The stannides RE2Ni2Sn (RE=Pr, Ho, Er, Tm) were synthesized by arc-melting of the elements and characterized by powder X-ray diffraction. Pr2Ni2Sn crystallizes with the orthorhombic W2B2Co-type structure, Immm, a=443.8(1), b=572.1(1), c=855.1(2) pm, wR2=0.0693, 293 F2 values, 13 variables. A structural transition to the tetragonal Mo2B2Fe type occurs for the heavier rare earth elements. The structures of Ho2Ni2Sn (a=729.26(9), c=366.66(7) pm, wR2=0.0504, 250 F2 values, 12 variables), Er2Ni2Sn (a=727.2(2), c=364.3(1) pm, wR2=0.0397, 262 F2 values, 12 variables), and Tm2Ni2Sn (a=725.2(1), c=362.8(1) pm, wR2=0.0545, 258 F2 values, 12 variables) were refined from single-crystal diffractometer data. The switch in structure type is driven by the size of the rare earth element. The [Ni2Sn] substructures are composed of Ni2Sn2 squares and Ni4Sn2 hexagons in Pr2Ni2Sn, and of Ni3Sn2 pentagons in Er2Ni2Sn. The Ni4Sn2 hexagons and Ni3Sn2 pentagons exhibit Ni2 pairs with Ni-Ni distances of 247 pm in Pr2Ni2Sn, and of 250 pm in Er2Ni2Sn.

Aquatic geochemistry of the rare earth elements and yttrium in the Pioneer River catchment, Australia

2006 ◽  
Vol 57 (7) ◽  
pp. 725 ◽  
Author(s):  
Michael G. Lawrence ◽  
Stacy D. Jupiter ◽  
Balz S. Kamber
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earth Element ◽  
Earth Element ◽  
River Catchment ◽  
Marine Source ◽  
Freshwater System ◽  
Gd Anomaly ◽  
Local Geology ◽  
The Rare Earth

The rare earth elements are strong provenance indicators in geological materials, yet the potential for tracing provinciality in surface freshwater samples has not been adequately tested. Rare earth element and yttrium concentrations were measured at 33 locations in the Pioneer River catchment, Mackay, central Queensland, Australia. The rare earth element patterns were compared on the basis of geological, topographical and land-use features in order to investigate the provenancing potential of these elements in a small freshwater system. The rare earth element patterns of streams draining single lithological units with minor land modification show strongly coherent normalised behaviour, with a loss of coherence in agricultural locations. Evidence is reported for an anthropogenic Gd anomaly that may provide a useful hydrological tracer in this region since the introduction of magnetic resonance imaging in 2003. Several samples display a superchondritic Y/Ho mass ratio (up to 44), which is not explainable within the constraints imposed by local geology. Instead, it is suggested that the additional Y is derived from a marine source, specifically marine phosphorites, which are a typical source of fertiliser phosphorus. The data indicate that, under some circumstances, scaled and normalised freshwater rare earth patterns behave conservatively.

scholarly journals Application of Deep Learning Algorithms in Determination of Trace Rare Earth Elements of Cerium Group in Rocks and Minerals

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Sumin Ma ◽  
Wenhui Huang
Keyword(s):  
Deep Learning ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Target Detection ◽  
Rare Earth Element ◽  
Earth Element ◽  
Experimental Results ◽  
Series Data ◽  
Data Set ◽  
The Rare Earth

Since the breakthrough of deep learning in object classification in 2012, extraordinary achievements have been made in the field of target detection, but the high time and space complexity of the target detection network based on deep learning has hindered the technology from application in actual product. To solve this problem, first of all, this paper uses the MobileNet classification network to optimize the Faster R-CNN target detection network. The experimental results on the rare earth element detection data set show that the MobileNet classification network is not suitable for optimizing the Faster R-CNN network. After that, this paper proposes a classification network that combines VGG16 and MobileNet, and uses the fusion network to optimize the Faster R-CNN target detection network. The experimental results on the rare earth element detection data set show that the Faster R-CNN target detection network optimized by the fusion classification network has the advantages of using VGG16 and MobileNet’s Faster R-CNN target detection network to detect rare earth elements. The innovation of this article is that the results on 5 time series data sets show that CDA-WR has better predictive performance than other ELM variant models. The effect of determining trace cerium elements in rocks and minerals is increased by more than 50%, based on deep learning. The algorithm studies the methods of target detection and recognition and integrates it into the intelligent robot used in this subject, giving the robot the ability to accurately detect the target object in real time.

Flame spectra of the rare-earth elements*

1962 ◽  
Vol 18 (4) ◽  
pp. 1127-1153
Author(s):  
V FASSEL ◽  
R CURRY ◽  
R KNISELEY
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
The Rare Earth
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