Effect of Rare Earth Additions on Grain Refinement of
Rare earth element cerium is an efficient grain refiner. In this paper, four different cerium contents are added to 18-carat Au–Ag–Cu–Zn alloys. The microstructures of these kinds of as-cast ...
اقرأ أكثر
Growth Kinetics of Core-Shell-Structured Grains and
The solute-drag-dependent growth kinetics of core-shell-structured grains in rare-earth-doped BaTiO3 ceramics was studied based on an analytical description of the diffusion of rare-earth atoms doped.
اقرأ أكثر
Exploring the mechanism of "Rare Earth" texture …
The effect of rare earth element segregation on grain boundary energy and mobility in magnesium and ensuing texture …
اقرأ أكثر
Grain Boundary Strengthening in Alumina by Rare …
Several simple models to explain the increase in GB creep resistance due to rare earth impurity doping have been proposed (4, 5), but the atomic-scale mechanism of how these dopants actually strengthen …
اقرأ أكثر
Phase Stability of Nanocrystalline Grains of Rare-Earth …
Rare-earth (RE) oxides are important in myriad fields, including metallurgy, catalysis, and ceramics. However, the phase diagram of RE oxides in the nanoscale might differ from the phase diagrams for bulk, thus attracting attention nowadays. We suggest that grain size in the nanoscale also determine …
اقرأ أكثر
Rare-earth element partitioning between sphene and
Over 80 sets of partition coefficients (D) for 4 rare-earth elements (REE) (La, Sm, Ho, Lu) partitioning between sphene and coexisting silicate liquid at 7.5 to 30 kbar and 900° to 1120°C, demonstrate that D-values increase with: (a) increasing SiO 2 content of the coexisting liquid; (b) increasing pressure; and (c) decreasing …
اقرأ أكثر
Recent advances on grain refinement of magnesium rare-earth …
High-performance cast magnesium rare-earth (Mg-RE) alloys are one of the most important materials among all developed Mg alloy families, and have shown great potential in military and weapons, aerospace and aviation, orthopedic implants, etc. Controlling grain size and distribution of it is key to the promising mechanical …
اقرأ أكثر
Statistical Analysis of the Inclusions in Rare Earth-M
The size, quantity, morphology and structure of inclusions in steel treated with rare earth (RE) with different deoxidizers (calcium and titanium) were studied. The difference between automatic and manual inclusion statistical analyses was investigated. The results showed that: RE tended to refine the inclusions and increase the number …
اقرأ أكثر
Grain-size effect on rare earth elements in Pahang River and …
Comparisons between rare earth elements, multi-elemental ratios, geo-accumulation index (Igeo), and bio-concentration factor (BCF) for the two mangroves and the influence of sediment grain size ...
اقرأ أكثر
Grain-size effect on rare earth elements in Pahang River and …
Grain size is an important controlling factor of the chemical composition of sediments. To understand the role of grain size in the content of rare earth elements (REE) in tropical mountainous river sediments and to establish suitable provenance proxies, sediments collected from Pahang River and Kelantan River, Peninsular Malaysia, were …
اقرأ أكثر
Effects of rare earth elements addition on …
Results show that rare earth elements can refine grains, improve hardness, tensile strength, and impact absorption energy of GCr15 bearing steel under different heat treatment conditions. Besides, it has been found that rare earth elements are beneficial …
اقرأ أكثر
Effects of various rare earth oxides on morphology and size …
Therefore, it is considered that the presence of rare earth composite oxides promotes the growth of W grains. 3.4 Comparative analysis of reduction process between ultrafine ODS-Mo and ODS-W alloy powders In the overall carbothermal reduction process of ODS-Mo composite powder, due to the lower reduction temperature from MoO3 to …
اقرأ أكثر
Segregation‐controlled densification and grain …
Segregation-controlled densification and grain growth in rare earth-doped Y 2 O 3. Moritz Kindelmann, Ke Ran, Wolfgang Rheinheimer, Koji Morita, Joachim Mayer, Martin Bram, Olivier Guillon. First published: …
اقرأ أكثر
These 13 Ancient Grains of the World May Hold the Key to …
An Ethiopian ancient grain, Teff is said to be the tiniest grain on earth; it is 150 times smaller than a single wheat kernel. When ground into a flour, it's used to make the Ethiopian staple injera, a spongy fermented flatbread. ... forbidden rice or chak hao is a rare and nutritious grain offering the many health benefits found in ...
اقرأ أكثر
Effects of grain size and temperature on slip and twinning …
Understanding the deformation mechanisms in magnesium alloys is critical to develop the next-generation high-performance magnesium alloys. In this work, the effects of grain size and temperature on slip and twinning activities in WE43 magnesium-rare earth alloy were investigated with the quasi-in-situ electron backscattering diffraction method …
اقرأ أكثر
Properties improvement and structural optimization of
Non-rare earth compound (MgO) is employed for NdFeB grain boundary diffusion. • Improvements of the magnetic properties and corrosion resistance are obtained. • MgO can modify the composition and structure of the grain boundary phase. • This process has great significance in minimizing the use of rare earth.
اقرأ أكثر
Grain Refinement Mechanism of Rare Earth Elements …
Grain Refinement Mechanism of Rare Earth Elements (Ce, Y and Gd) on AZ91 Magnesium Alloy at Different Cooling Rates. Technical Paper. Published: 01 …
اقرأ أكثر
Microstructure and performance of rare earth …
Alloying elements such as Re, Hf, Zr, and Nb help modify impurity distributions and effectively strengthen the grain boundaries of W 13. In addition, rare-earth (RE) elements such as La and Y show ...
اقرأ أكثر
Look between the grains | Nature Geoscience
When accounting for the trace element inventories in the crystal lattices of rock-forming mineral grains only, the bulk concentrations of incompatible trace elements …
اقرأ أكثر
Strengthening of low-cost rare earth magnesium alloy Mg …
The grain size is significantly refined, reaching 1.14 μm. (1) The strength enhancement of the low-cost rare-earth magnesium alloys after MDF is related to solid solution strengthening and more attributed to the combined effect of the grain refinement and aging precipitates. (2)
اقرأ أكثر
Modifying Tb-Cu grain boundary diffusion behavior in Nd
The grain boundary diffusion using mixed rare earths (REs) as the diffusion source is very effective in enhancing the coercivity of Nd-Fe-B magnets. Here, we firstly investigated the Gd added Tb-Cu diffusion alloys and found that the coercivity of Nd-Fe-B magnets can be improved from 1094 kA/m to 1704, 1677 and 1593 kA/m by Tb 70 Cu 30 …
اقرأ أكثر
First-Principles Study of Rare-Earth Effects on Grain Growth …
The results indicated that in situ growth of elongated 6H-SiC grains was caused by rare earth elements together with the liquid Ba-Al-Si-O system. The type and content of rare earth oxides had a ...
اقرأ أكثر
Effect of rare earth elements on the microstructure and …
Larger grains develop a texture with a distinct component at the 〈11.1〉 pole, while smaller ones show a texture closer to the original 〈10.0〉 fibre component. Depending on the rare earth element and how far the microstructure develops during recrystallisation, a shift towards the 〈11.1〉 pole is also visible but not distinct.
اقرأ أكثر
Nucleation and preferential growth mechanism of
Rare earth element additions and stored energy from deformation work in combination to alter texture in rare earth element containing magnesium alloys. The nucleation stage of dynamic recrystallization was explored in samples with partially recrystallized microstructures, revealing necklace structures of small grains forming …
اقرأ أكثر
Diffusion behavior of heavy rare-earths for grain boundary …
The 2-powder method (2PM) for the production of high-performance Nd 2 Fe 14 B-based sintered magnets consists of blending a coarser heavy rare-earth (HRE) free main phase powder (here D 50 = 5.3 µm) and a finer HRE-containing anisotropy powder (here D 50 = 2.6 µm) of Dy content of 10 wt.%. The development of the core-shell structure was …
اقرأ أكثر
Toward deformability enhancement of rare earth …
After the plastic deformation of rare earth magnesium alloys, the grain size was refined obviously and the stress inside the materials is larger. Therefore, the grain boundary is very blurred under OM, so the Electron Backscattered Diffraction (EBSD, Nordly Max 3) as a powerful tool for grain orientation, size distribution, boundary …
اقرأ أكثر
Growth kinetics of core-shell-structured grains and dielectric …
The solute-drag-dependent growth kinetics of core-shell-structured grains in rare-earth-doped Ba Ti O 3 ceramics was studied based on an analytical description of the diffusion of rare-earth atoms doped. Dependence of the sizes of grain core and shell on the sintering conditions, dopant content, and starting powder size was quantitatively revealed.
اقرأ أكثر
Thermal Analysis of Rare Earth Grain Refined 4130
This paper discusses the thermal analysis of rare earth grain refined 4130. To accomplish this, heats of 4130 Baseline, 0.3 wt% RE silicide, and 0.3 wt% EGR were poured in a thermal analysis cup with a single S-type thermocouple at the bottom. A data acquisition system recorded the cooling curves whose values were compared to reference data.
اقرأ أكثر
Metals | Free Full-Text | Additive Manufacturing of …
With the rapid development of intelligent manufacturing, modern components are accelerating toward being light weight, miniaturized, and complex, which provides a …
اقرأ أكثر
Development of non-rare earth grain boundary
This review summarizes the development of grain boundary modification techniques with emphasis on our recent work using cost-effective non-rare earth (non-RE) sources for GBD. Up to now, heavy rare earth (HRE) based compounds, metals and light rare earth (LRE) based alloys have been successfully employed as the diffusion sources …
اقرأ أكثر