Preparation and sintering of fine molybdenum powder

Tuominen, S.M.

doi:10.1016/0032-5910(81)85027-9

Cited by 14 publications

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“…Relative densities of commercial Mo powders have been reported previously in the literature. Tuominen [17] reported a relative density value of about 96% at a sintering temperature of 1790 • C with a holding time of 16 h. Savin [18] reported relative densities of about 78 and 82% at sintering temperatures of 1500 and 1700 • C, respectively, and Sukhozhak et al [19] reported a relative density value about 94% at a sintering temperature of 1400 • C with a holding time of 1 h. Considering the reported sintering densities of Mo powder, it is clear that the nanopowder requires less sintering time or lower temperature for densification to occur to the same extent as with commercial powder. Fig.…”

Section: Resultsmentioning

confidence: 99%

Densification behavior of Mo nanopowders prepared by mechanochemical processing

Kim

et al. 2009

Journal of Alloys and Compounds

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Section: Resultsmentioning

confidence: 99%

Densification behavior of Mo nanopowders prepared by mechanochemical processing

Kim

et al. 2009

Journal of Alloys and Compounds

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“…The solution was purified by ion exchange chromatography using a Dowex 50W-X8 cation exchange column (50 · 2 cm diameter). The eluate containing molybdic acids (MoO 3 Án H 2 O) was evaporated to dryness and reduced to molybdenum metal in a tube furnace at 1,100°C under a hydrogen atmosphere (22,23).…”

Section: Recycling Of 100 Momentioning

confidence: 99%

Implementation of Multi-Curie Production of ^99mTc by Conventional Medical Cyclotrons

et al. 2014

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99m Tc is currently produced by an aging fleet of nuclear reactors, which require enriched uranium and generate nuclear waste. We report the development of a comprehensive solution to produce 99m Tc in sufficient quantities to supply a large urban area using a single medical cyclotron. Methods: A new target system was designed for 99m Tc production. Target plates made of tantalum were coated with a layer of 100 Mo by electrophoretic deposition followed by high-temperature sintering. The targets were irradiated with 18-MeV protons for up to 6 h, using a medical cyclotron. The targets were automatically retrieved and dissolved in 30% H 2 O 2 . 99m Tc was purified by solid-phase extraction or biphasic exchange chromatography. Results: Between 1.04 and 1.5 g of 100 Mo were deposited on the tantalum plates. After high-temperature sintering, the 100 Mo formed a hard, adherent layer that bonded well with the backing surface. The targets were irradiated for 1-6.9 h at 20-240 μA of proton beam current, producing up to 348 GBq (9.4 Ci) of 99m Tc. The resulting pertechnetate passed all standard quality control procedures and could be used to reconstitute typical anionic, cationic, and neutral technetium radiopharmaceutical kits. Conclusion: The direct production of 99m Tc via proton bombardment of 100 Mo can be practically achieved in high yields using conventional medical cyclotrons. With some modifications of existing cyclotron infrastructure, this approach can be used to implement a decentralized medical isotope production model. This method eliminates the need for enriched uranium and the radioactive waste associated with the processing of uranium targets.

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“…Since molybdenum metal products are predominately produced employing powder metallurgy techniques, the pressing and sintering of molybdenum powder has been investigated in great detail. [2][3][4][5][6] However, molybdenum powders can have widely varying characteristics and thus information concerning compaction and sintering varies significantly. Therefore, in an earlier study, molybdenum powders from various sources were evaluated to determine the effects of powder characteristics and processing parameters such as compaction pressure and sintering temperature on the properties of the densified product.…”

Section: Introductionmentioning

confidence: 99%

Powder Metallurgy Fabrication of Molybdenum Accelerator Target Disks

Lowden¹,

Kiggans²,

Nunn³

et al. 2015

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Powder metallurgy approaches for the fabrication of accelerator target disks are being examined to support the development of Mo-99 production by NorthStar Medical Technologies, LLC. An advantage of powder metallurgy is that very little material is wasted and at present, dense, quality parts are routinely produced from molybdenum powder. The proposed targets, however, are thin wafers, 29 mm in diameter with a thickness of 0.5 mm, with very stringent dimensional tolerances. Although tooling can be machined to very high tolerance levels, the operations of powder feed, pressing and sintering involve complicated mechanisms, each of which affects green density and shrinkage, and therefore the dimensions and shape of the final product. Combinations of powder morphology, lubricants and pressing technique have been explored to produce target disks with minimal variations in thickness and little or no distortion. In addition, sintering conditions that produce densities for optimum target dissolvability are being determined.

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Preparation and sintering of fine molybdenum powder

Cited by 14 publications

References 0 publications

Densification behavior of Mo nanopowders prepared by mechanochemical processing

Densification behavior of Mo nanopowders prepared by mechanochemical processing

Implementation of Multi-Curie Production of ^99mTc by Conventional Medical Cyclotrons

Powder Metallurgy Fabrication of Molybdenum Accelerator Target Disks

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Preparation and sintering of fine molybdenum powder

Cited by 14 publications

References 0 publications

Densification behavior of Mo nanopowders prepared by mechanochemical processing

Densification behavior of Mo nanopowders prepared by mechanochemical processing

Implementation of Multi-Curie Production of 99mTc by Conventional Medical Cyclotrons

Powder Metallurgy Fabrication of Molybdenum Accelerator Target Disks

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Product

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Implementation of Multi-Curie Production of ^99mTc by Conventional Medical Cyclotrons