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 …

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 …

1. Introduction. Nd-Fe-B permanent magnets have been widely used in the field of renewable energy applications with high working temperatures [1].Since the Nd 2 Fe 14 B main phase (2:14:1 phase) exhibits a rapid decrease in anisotropy field (H A) with increasing temperature and low Curie temperature [2], heavy rare earth (HRE) elements …

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 ...

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: …

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 ...

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 …

Meanwhile, adding rare earth elements can also reduce the residual stress and cracking sensitivity of the composite coatings [16], [17], [18]. In particular, La is a typical grain boundary segregation element and surface-active element, and its pinning effect can inhibit the growth of grains and achieve the effect of grain refinement.

The effect of rare earth element segregation on grain boundary energy and mobility in magnesium and ensuing texture weakening. Scr. Mater. 146, 46–50 (2018).

@article{Wu2018TheDT, title={The dual trend of diffusion of heavy rare earth elements during the grain boundary diffusion process for sintered Nd-Fe-B magnets}, author={Binghui Wu and Ding Xuefeng and Qingke Zhang and Lijing Yang and Bizhang Zheng and Fanting Hu and Zhenlun Song}, journal={Scripta Materialia}, year={2018}, …

Grain Refinement Mechanism of Rare Earth Elements (Ce, Y and Gd) on AZ91 Magnesium Alloy at Different Cooling Rates. Technical Paper. Published: 01 …

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.

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.

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 …

The addition of rare earth to high manganese austenitic steel can refine the grains and make the carbides distributed uniformly, improving the strength and plastic toughness of high manganese steel [].Adding rare earth in tool steel D2 can refining the as cast microstructure and provide heterogeneous nucleation core for the formation of …

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 ...

The material used in this study is a commercial as-cast rare earth magnesium alloy (hereinafter referred to as AC) with a thickness of 17 mm, and its composition is tested as shown in Table 1.Multi-pass repeated hot rolling was used with the thickness of the sheet reduced from 17mm to 3mm (RR), and the temperature was kept at 500 °C for 15 min …

Notably however, some small grains in pure Mg are observed which have the characteristic "rare-earth" orientation. These grains are infrequent and do not grow significantly. In contrast, the 10 1 ¯ 0 and 2 1 ¯ 1 ¯ 0 pole …

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 …

Grain boundary diffusion (GBD) process is an effective method to fabricate high-coercive Nd-Fe-B magnets with less consumption of heavy rare earth (HRE). By this approach, HRE-rich shell forms around the Nd2Fe14B grain, which can hinder the magnetic reversal starting at the edge of the grains and enhance the coercivity of whole magnet. …

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 …

The effect of rare earth element segregation on grain boundary energy and mobility in magnesium and ensuing texture weakening. Scripta Mater. 146, 46–50 …

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 ...

The grain refinement effects of REs on AZ91 magnesium alloy are mainly due to the rare earth compounds of Al 4 Ce, Al 2 Y and Al 2 Gd which can act as heterogeneous nucleation particle to promote nucleation and the inhibitory effects of rare earth compounds distributed near grain boundaries on the grain growth.

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)

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 …

The results showed that the grain size and volume curve of rare earth ore have unimodal and bimodal shapes, respectively. X-ray diffraction showed the …

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 …

With the rapid development of intelligent manufacturing, modern components are accelerating toward being light weight, miniaturized, and complex, which provides a …

Contrary to the results obtained by Zhou et al., 66 Cheng et al., 67 and Luo et al., 68 an evolution route resulting in the final production of Ce–O and Ce–O–S was reported, of which the morphology and elemental mapping of inclusions are shown in Fig. 2. 71 For example, Huang et al. 72 added Ce to H13 steel and found that Ce could …