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Metals
Published in Ronald M. Scott, in the WORKPLACE, 2020
Beryllium finds use as an alloying agent, particularly to strengthen copper, but also with aluminum, magnesium, and steel. Beryllium oxide is used in ceramics. However, the uses of beryllium that have increased most rapidly in recent decades are as a moderator in atomic reactors, and as a structural component in space vehicles.
An Overview of the Recent Status of Critical and Strategic Metal Production and Development in India
Published in Abhilash, Ata Akcil, Critical and Rare Earth Elements, 2019
B.D. Pandey, Abhilash, Pratima Meshram
Though the use of calcium chloride as a booster is economical, the use of excess (40%) of BeF2 in the reaction mixture yields the best results, which forms a thin coating over MgF2 crystals and rapidly dissolves while ball milled in the presence of water, disintegrating the slag and releasing the beryllium pebbles. The metal pebbles are refined by vacuum induction melting. The vacuum cast ingot is further processed using powder metallurgy (P/M) to produce hot-pressed beryllium blocks, which are precision machined to form various components for space and other related applications. However, for nuclear-grade beryllium, beryllium oxide of high purity is required, which is obtained by processing beryllium hydroxide by beryllate- and carbonate-based processes to produce beryllia of above 99.9% purity.
A new generation of highly efficient and long-term industrial sealed-off active elements of pulsed copper vapour lasers of the Kulon series with a radiation power of 1–20 W and Kristall series with a power of 30–100 W
Published in A.G. Grigor’yants, M.A. Kazaryan, N.A. Lyabin, Laser Precision Microprocessing of MaterialsLaser Precision Microprocessing of Materials, 2019
A.G. Grigor’yants, M.A. Kazaryan, N.A. Lyabin
As a material of the tubes (items 2 and 6) and bushings (item 3) of the discharge channel (item 1) with an operating temperature of up to 1600°C, by means of a compromise analysis of the properties of high-temperature oxides, was A-995 ceramics of the composition 99.8% Al2O3+ 0.2% MgO with a melting point of 2050°C produced by the Istok Co. [16, Ch. 2], Although as regards the physicochemical properties the preferred material for tubes and bushings of the discharge channel is ceramics from beryllium oxide (BeO) [13]. The melting point of ceramics from BeO is above 2500°C, the vapour pressure of the compound at operating temperature is less than 10−5 mm Hg (Al2O3–103 mm Hg). The BeO oxide in comparison with Al2O 3 has 2.5 times higher thermal conductivity (14.5 and 5.8 W/(m·deg)) and 1.4 times less specific gravity (2.7–2.8 and 3, 7–3.8 g/cm3) and, accordingly, better withstands thermal shock during heating. But the beryllium oxide has a significant drawback – high toxicity, which creates serious technological problems in the manufacture of devices. In addition, in Russia the production of ceramic tubes from BeO does not exist anymore and it is expensive.
Computational simulation of IC engine cooling using different materials for different shapes of fins: a comparative study
Published in International Journal of Ambient Energy, 2023
Md Iftekharul Alam, Ahmad Abdullah Mujahid, Bodius Salam
In this study, there were 4 types of materials used in the transient thermal simulation in 4 different shaped fins. Aluminium 6061 alloy was used as the engine cylinder material. Aluminium 6061, Aluminium 2014,and Silicon carbide-Aluminium 2124 (SiC-Al 2124 25%) were chosen as these materials have good thermal properties and were used in (Dubey et al., 2017; Sagar et al. 2017). Beryllium oxide (BeO) was also chosen for having better thermal conductivity and melting temperature than Aluminium 6061, Aluminium 2014, and Silicon Carbide-Aluminium 2124 (SiC-Al 2124 25%). Again, BeO is lighter than Aluminium 2014 and for these reasons, BeO was chosen for the present study. The properties of the fins are given in Table 1. The properties of the materials which were used in these fins are provided in Table 2. The material characteristics of Aluminium 6061 were obtained from Seli et al. (Seli et al. 2013). The properties of Aluminium 2014 alloy were from online data (Aluminum 2014 Alloy | AMERICAN ELEMENTS ®, n.d.). The properties of Beryllium Oxide were from online data (Beryllia (Beryllium Oxide, BeO):: MakeItFrom.Com, n.d.). Again, the properties of SiC-Al 2124(25%) alloy were from (Evans et al., 2003). Since, (Babu & Lavakumar, n.d.) reduced fin thickness from 3 mm to 2.5 mm, in this present study 2 mm of fin thickness was used to reduce the weight of fin bodies. As (Evans, San Marchi, and Mortensen 2017) used different slots of 5 mm, 7.5 mm, 10 mm with 2.35 mm thickness, 5 mm slot size was also used in slotted fins with 2 mm thickness in this present study. Sinusoidal equations were used to create the wavy-shaped fins.
Overview of biological mechanisms of human carcinogens
Published in Journal of Toxicology and Environmental Health, Part B, 2019
Nicholas Birkett, Mustafa Al-Zoughool, Michael Bird, Robert A. Baan, Jan Zielinski, Daniel Krewski
Beryllium is an uncommon metal that is used primarily in alloys or in beryllium oxide ceramics. Beryllium produces lung cancer in occupational settings. Inhalation seems to be required for carcinogenesis. There is no apparent evidence of a cancer risk from ingestion of beryllium.
Development and potential of composite moderators for elevated temperature nuclear applications
Published in Journal of Asian Ceramic Societies, 2022
Lance L Snead, David Sprouster, Bin Cheng, Nick Brown, Caen Ang, Edward M Duchnowski, Xunxiang Hu, Jason Trelewicz
Beryllium oxide ceramic is a relatively high thermal conductivity material produced through any number of powder-processing and sintering routes, not dissimilar to the powder metallurgy products approaches depicted for Be (cf. Figure 2.) Its production is typical of a “porcelain process” of powder (slurry or dry) preparation, molding, and sintering. BeO has found a range of boutique applications driven by its oxidation resistance and combined high thermal conductivity and operating temperature capability. Given the strongly covalent nature of BeO it has a relatively high melting and sintering temperature for pure powder (2570 and >1900°C, respectively). This sintering temperature can be suppressed through addition of second phase aids such as Al2O3 or MgO, though with significantly negative impact on properties such as thermal conductivity. Non-nuclear applications include power semiconductor devices and as structural components in high-performance microwave devices and lasers. Historically, nuclear ceramics have been fabricated from pure BeO powder or from powders which include minor additives such as MgO or (nuclear grade) ZrO2, which has been used to stabilize a small-grained microstructure, added as powder sintering aids or a sol [40,41]. Development and study of BeO for nuclear application dates back almost as far as graphite, with BeO being the candidate reflector material (and also a core material) for the Daniel’s Pile, the first conceptual design of a high-temperature gas-cooled reactor (HTGR) [40,42]. However, while considerable work BeO technology was carried out that HTGR project was ultimately canceled due to funding priorities and the aggressive nature of the technology (at that time.) Regardless, fundamental investigations into the irradiation damage in the BeO system and formation of BeO ceramics continued and the material was used widely in a number of reactor systems. As example of progress toward process, the Daniels Pile project routinely produced BeO powders of >95.5% purity and fabricated hexagonal moderator blocks of 15 cm in length and 7.6 cm across the flats. Two reactor example nuclear applications successfully deploying BeO ceramics are provided in Figure 3: (a) provides a top-down view of the Aircraft Reactor Experiment, which operated in 1954 and was comprised of pure BeO hexagonal bars (of the Daniels Reactor Project vintage) through which a 53.09 mole % NaF, 40.73 mole % ZrF4, and 6.18 mole % UF4 liquid fuel was passed, and (b) providing an image of the Kilopower space reactor which was tested in 2018, a solid cast 93% 235U and 7% Mo fuel surrounded by BeO reflector.