Ndfeb hydrogen decrepitation.jpeg.

Feb 9, 2023 · Abstract The process of hydrogen decrepitation of the (Nd, Pr, Dy)(Fe, Co)2.6 alloy in wide temperature and pressure ranges has been studied. The choices of the chemical composition of the (Nd, Pr, Dy)(Fe, Co)2.6 alloy and the method of production of the initial alloy based on out-of-furnace calcium–thermal reduction are substantiated. The introduction of dysprosium into the alloy ... The high- and standard-grade material can be processed using either an HD/HDDR process or a sintering process, both of which are being tested in the course of this project. HD/HDDR stands for hydrogen decrepitation (HD) and hydrogen-disproportionation decomposition-recombination (HDDR). The HD/HDDR pulverised …A production-scale plant in Germany planned to go onstream in 2024 and a pilot plant launched a few months ago in the UK, expected to graduate to production-scale in 2023, are using the hydrogen-enabled process in efforts to commercialize it. At the center of both efforts is HyProMag Limited, closely tied to the University of Birmingham and an ...Hydrogen Decrepitation and Recycling of NdFeB-type Sintered Magnets. Miha Zakotnik, E. Devlin, +1 author. A. Williams. Published 2006. Materials Science, Engineering. Journal of Iron and Steel Research International. View via Publisher. Save to Library.

Mar 1, 2019 · Fig. 1 shows the hydrogen decrepitation curves of Nd-Fe-B SC and SM at 288 K with different initial hydrogen pressure. Under the initial hydrogen pressure of 0.1–1 Mpa, the HD process composes of four stages of magnets surface activation, slow hydrogenation of Nd-rich grain boundary phase, quick hydrogenation of Nd 2 Fe 14 B main phase grains, and slow hydrogenation of inner part of the magnets. Sadly, one of the most common RE magnets, NdFeB, is produced as powder by strip casting and jet milling or by hydrogen decrepitation process, both of which yield irregular/angular powders. Such irregular powders exhibit low flowability making them unfit for most advanced manufacturing techniques. This work presents the use of an induction ...

High-temperature demagnetization can, however, cause melting of components, e.g., plastics, glue, etc. Hydrogen decrepitation (Table 8.3), a more efficient alternative, has been suggested for processing of HDDs [34], [35]. The NdFeB magnets absorb hydrogen, expanding in volume with about 5%, which causes breaking into …

Semantic Scholar extracted view of "Possible methods of recycling NdFeB-type sintered magnets using the HD/degassing process" by M. Zakotnik et al. ... The purpose of this thesis was to study the Hydrogen Decrepitation (HD) process as a way to recycle waste scraps of Nd-Fe-B sintered magnets into highly coercitive and anisotropic …NdFeB magnets are used in wind turbines and hybrid electric vehicles and are instrumental in progression toward a low-carbon economy. Recycling rare-earth elements (REEs) from NdFeB magnet waste is an important step toward building a sustainable REE supply chain. In this study, we describe an electrochemical process to selectively extract REEs from NdFeB magnet waste at room temperature. First ... magnets. The thermal and mechanical impact of the hydrogen decrepitation process was assessed during hydrogen processing. For all forms of sintered NdFeB scrap the surface condition of the magnets is important as oxidation has been shown to inhibit the onset of the hydrogen decrepitation process. In this Hydrogen decrepitation (HD) of the sintered block was used to return the annealed material back into a powder [33]. During this step, the material reacts with hydrogen resulting in volume expansion of both the Nd-rich phase, at triple junctions and grain boundaries, and the Nd 2 Fe 14 B matrix phase [34]. This expansion leads to …These magnets were identical in every way apart from the orientation of the Nd 2 Fe 14 B grains. Each magnet was exposed to hydrogen and the decrepitation behaviour observed. The anisotropic samples were found to decrepitate exclusively from the ends of the rods whereas the isotropic magnets were attacked by the hydrogen at all …

In this paper it is demonstrated that hydrogen could play a vital role in this process. Fully dense sintered NdFeB-type magnets have been subjected to the hydrogen decrepitation (HD) process.

Hydrogen decrepitation (HD) of Nd-Fe-B cast alloys is widely used in the processing of sintered magnets. The oxidation resistance under air of alloy powder …

The nature of hydrogen decrepitation when applied to a cast Nd-Fe-B permanent magnet alloy has been studied by following the microstructural changes on polished surfaces of the material exposed to hydrogen at a pressure of 4 bar. The milling of the material decrepitated at a pressure of 10 bar has also been studied by determining …The HD-process converts the magnets possible to recover the hard magnetic powder from a to a powder due to the expansion of the material on particular device (e.g. hard disk drive or electric motor) hydrogen absorption. Recycling of NdFeB magnets by by simply exposing the complete system to a hydrogen this means has been proposed by Rivoirard ...magnets. The thermal and mechanical impact of the hydrogen decrepitation process was assessed during hydrogen processing. For all forms of sintered NdFeB scrap the surface condition of the magnets is important as oxidation has been shown to inhibit the onset of the hydrogen decrepitation process. In thisApr 15, 2022 · An effective and complete processing route for the recycling of sintered Nd-Fe-B scrap magnets was proposed. Sintered Nd-Fe-B magnets were subjected to the Hydrogen Decrepitation (HD) process at various temperatures in the range of 50–300 °C, at two different pressures, 50 kPa and 200 kPa, followed by vacuum dehydrogenation in the range of 720–820 °C. As noted above, the calculated Gibbs energy of reactions of individual REE with atomic hydrogen (Table 1) is strongly negative, thereby predictive of rapid chemical decrepitation of the two-phase Nd-magnet within the temperature range of interest. These reactions can be expected to take place immediately … See moreA production-scale plant in Germany planned to go onstream in 2024 and a pilot plant launched a few months ago in the UK, expected to graduate to production-scale in 2023, are using the hydrogen-enabled process in efforts to commercialize it. At the center of both efforts is HyProMag Limited, closely tied to the University of Birmingham and an ...

A bulk ingot of a Nd-Fe-B alloy has been powdered by a combination of hydrogen decrepitation and attritor milling. The powder was aligned and pressed in the hydrided condition and the green compact sintered at 1080‡ C for 1 h after an appropriate heating rate. Excellent densities were achieved after this procedure and the magnets produced …Sintered Nd-Fe-B magnets were subjected to the Hydrogen Decrepitation (HD) process at various temperatures in the range of 50-300°C, at two different pressures, 50 kPa and 200 kPa, followed by ...Hydrogen decrepitation (HD) of the sintered block was used to return the annealed material back into a powder [33]. During this step, the material reacts with hydrogen resulting in volume expansion of both the Nd-rich phase, at triple junctions and grain boundaries, and the Nd 2 Fe 14 B matrix phase [34]. This expansion leads to …Hydrogen decrepitation (HD) of Nd-Fe-B cast alloys is widely used in the processing of sintered magnets. The oxidation resistance under air of alloy powder …The behavior of hydrogen absorption and release in hydrogen decrepitation (HD) process of Nd-Fe-B alloys were investigated. The results reveal that the reactivity and the amount of hydrogen absorption in HD process are related to the surface activity of the alloy so that the fresh and active surface has a higher efficiency. The presence of Nd-rich phase at the …

The behavior of hydrogen absorption and release in hydrogen decrepitation (HD) process of Nd-Fe-B alloys were investigated. The results reveal that the reactivity and the amount of hydrogen absorption in HD process are related to the surface activity of the alloy so that the fresh and active surface has a higher efficiency. The presence of Nd-rich phase at the …The scrap sintered Nd–Fe–B magnets were recycled as the raw materials for bonded magnets using the hydrogen decrepitation (HD) process. The HD powders have the lowest oxygen and hydrogen content by hydrogenation at 150 °C with 1 bar H2 pressure and dehydrogenation at 600 °C. The powders with the largest particle size (>380 μm) …

The method combines hydrogen decrepitation (HD) disintegration of the initial magnet, powder sieving and the Press-Less Process (PLP), where hydride powder is sintered in a …As starting materials, magnets of different grades were used, which were processed by hydrogen decrepitation and blending the powder with NdH x. Composition inhomogeneity in the Nd 2 Fe 14 B-based magnetic phase grains in the recycled magnets and the existence of a core-shell structure consisting of a Nd-rich (Dy-depleted) core and …Mar 1, 1985 · The hydrogen decrepitation (HD) process are studied in detail based on these results. The hydrogen absorption mechanism of Sm(CoFeCuZr) 7.6 alloy can be regarded as a hydrogen dissolution process without phase transformation. In addition, the existence of a large amount of fine grains in the SC has an adverse effect on the alignment, which can ... High-temperature oxidation resistance of Nd–Fe–B magnetic powder is of great importance for its application in bonded magnet fields. In this work, the refinement and surface modification of Nd–Fe–B magnetic powders were integrated and achieved simultaneously. The effects of phosphoric acid, isopropyl tris-(dioctyl pyrophosphate …Dec 20, 2020 · Extraction of NdFeB from rotors using hydrogen. Seven semi-embedded rotors and non-embedded rotors were processed separately in two experiments. All the magnets in individual slots were scored in concentric circles using an angle grinder to provide a fresh surface for the hydrogen, as shown in Fig. 3, 15–30 min before being loaded into the ... A Hydrogen Decrepitation Press-Less Process (HD-PLP) recycling method for recycling of anisotropic NdFeB magnets is demonstrated. The method combines hydrogen decrepitation (HD) disintegration of the initial magnet, powder sieving and the Press-Less Process (PLP), where hydride powder is sintered in a graphite mold. The ultrafine magnet waste (particle size < 1 µm) contained around 50% rare earths mainly in the form of hydroxides as they are generated from the hydrogen decrepitation. The major phases in ultrafine NdFeB waste were Nd(OH) 3, Fe 2 O 3 and Fe phases. When ultrafine magnet waste was leached with hydrofluoric acid, all the iron …May 5, 2017 · The room temperature hydrogenation causes decrepitation of the material, where the Nd-rich material forms NdH 2.7 and the Nd 2 Fe 14 B matrix grains form an interstitial hydrogen solution. The material expands by ∼5% and because of its brittle nature and differential expansion, undergoes decrepitation [16].

Rare earth magnets based upon neodymium-iron-boron (NdFeB) are employed in many high tech applications, including h... Skip to main content. Sign In Create account . Journal Article OPEN ACCESS. THE USE OF THERMAL HYDROGEN DECREPITATION TO RECYCLE Nd-Fe-B MAGNETS FROM ELECTRONIC WASTE. Piotrowicz A; Pietrzyk S; …

A combination of hydrogen decrepitation (HD) and jet milling (JM) has been used to produce powder for the processing of permanent magnets. The procedure has proved to be very successful for both Nd-Fe-B (Neomax) alloys and the ND-Dy-Fe-Nb-B high coercivity alloys. The magnets produced by the HD/JM process showed excellent coercivities when …

Hydrogen decrepitation (HD) of Nd-Fe-B cast alloys is widely used in the processing of sintered magnets. The oxidation resistance under air of alloy powder …Sprecher, et al. [8] compared the environmental impact of producing virgin NdFeB magnets to producing recycled NdFeB magnets from waste computer hard disk drives (HDDs) using hydrogen decrepitation. The results showed that recycling in general was more favorable to the environment, and this was especially true for manual …The high- and standard-grade material can be processed using either an HD/HDDR process or a sintering process, both of which are being tested in the course of this project. HD/HDDR stands for hydrogen decrepitation (HD) and hydrogen-disproportionation decomposition-recombination (HDDR). The HD/HDDR pulverised …NdFeB ingot exposed to hydrogen atmosphere due to the changes of hydride lattice parameters cracks. The process called HDDR (Hydrogenation - …Hydrogen decrepitation process has been applied for the first time for the direct recycling of SmCo 5 magnets. Industrially produced sintered SmCo ... Nowadays, NdFeB magnets represent more than 90% of the REE permanent magnets production. But, SmCo magnets have much higher coercivity and better temperature resistance, and many experts expect ...Jan 1, 2007 · The rapid cooling of the strip flakes suppresses the growth of soft α-Fe branch crystal grains. The thickness of the strip flakes was about 0.25–0.35 mm. Hydrogen decrepitation (HD), which uses the expansion of hydrogen to break up the flakes, was followed by milling in a jet mill (JM). The particles were then accelerated to supersonic ... Finely divided loose Nd2Fe14BHx, x≤5, hydride powder (particle size ≤1 μm is synthesized by washing Nd2Fe14B crystallites embedded in calcium and other by‐products (during a reduction‐diffusion‐reaction performed using excess calcium) in water. The calcium reacts thereby with the water and produces, Ca+H2O CaO+H2, native …room temperature in a custom-made gauge glass reactor, and the hydrogen decrepitation process was video-monitored in situ with a single frame camera at 0.1 frames per second (fps).For the second type, three popular techniques, hydrogen decrepitation (HD), HDDR, and MS are applied to produce magnetic powders with the waste magnets. Note that the resultant powders prepared from the three techniques are single crystal powders, textured polycrystalline powders, and random aligned polycrystalline powders, respectively. ...Investigating the properties of recycled NdFeB magnets. We report investigations on the processing by Spark Plasma Sintering (SPS) of RE Fe B (RE Abstract 2 14 = Nd, Pr. . . ) powders obtained by hydrogen decrepitation of decommissioned magnets and the magnetic properties of the consolidated magnets.A study of the processing and characterisation of sintered NdFeB magnets made from recycled feed stock was undertaken. Initially the hydrogen decrepitated (HD) powder was investigated using two different milling techniques ball milling and burr milling. The powders were analysed with optical microscopy, with the aid of a magnetic field.It should be noted that hydrogen already plays a vital role in the production of sintered NdFeB-type magnets [1].The bulk alloy absorbs around 0.4 wt.% of hydrogen during the initial decrepitation stage and this hydrogen is desorbed during the subsequent vacuum sintering.Every tonne of alloy produces around 40 cubic meters of hydrogen …

In this paper it is demonstrated that hydrogen could play a vital role in this process. Fully dense sintered NdFeB-type magnets have been subjected to the …International Journal of Hydrogen Energy. Volume 24, Issues 2–3, 1 March 1999, Pages 257-261. Application of hydrogen vibration milling in theprocessing of NdFeB and (Nd, Pr)FeB permanent magnets. Author links open overlay panel R.S Mottram 1, V Yartys 2, P.W Guegan 1, I.r Harris 1. Show more.May 5, 2017 · The room temperature hydrogenation causes decrepitation of the material, where the Nd-rich material forms NdH 2.7 and the Nd 2 Fe 14 B matrix grains form an interstitial hydrogen solution. The material expands by ∼5% and because of its brittle nature and differential expansion, undergoes decrepitation [16]. Instagram:https://instagram. enhanced defense 5eandampsauandampved2ahukewjrg_2kjpabaxufm2ofhxf2b2mqfnoecagqagandampusgaovvaw3la_jjzd39lwpvmtmwikbdsauerkrautwhpuhfdyactnetmac wood Oct 25, 2015 · End-of-life NdFeB magnets are important secondary RE sources. Several recycling methods for NdFeB magnets have been developed, such as direct reuse,4 hydrogen decrepitation (HD) and regeneration of new NdFeB,5–7 pyrometallurgical methods,8,9 hydrometallurgical methods,10–13 gas-phase extraction. t bill ladderblogcraigslist sylmar High-temperature oxidation resistance of Nd–Fe–B magnetic powder is of great importance for its application in bonded magnet fields. In this work, the refinement and surface modification of Nd–Fe–B magnetic powders were integrated and achieved simultaneously. The effects of phosphoric acid, isopropyl tris-(dioctyl pyrophosphate … check lowe Dec 25, 2017 · Recycling of Nd-Fe-B magnets is one of the few solutions to alleviate the supply risks of certain rare earth elements (REE) such as Nd and Dy. One of the most promising solutions with regards to extraction of end-of-life (EOL) magnets is to apply hydrogen decrepitation and to physically separate the Nd-Fe-B as a demagnetized hydrogenated powder. 99.5%. The strips were employed in hydrogen decrepitation (HD) into coarse fragile particles. These coarse particles were then sent into jet milling (JM) procedure under a N. 2. gas flow. The dry powder was compacted of 14 mm diameter and 15 mm height with the alignment made with the maximum 2 T magnetic field.