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Permin D, Postnikova O, Balabanov S, Belyaev A, Koshkin V, Timofeev O, Li J. Influence of SHS Precursor Composition on the Properties of Yttria Powders and Optical Ceramics. MATERIALS (BASEL, SWITZERLAND) 2022; 16:260. [PMID: 36614599 PMCID: PMC9822065 DOI: 10.3390/ma16010260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/22/2022] [Accepted: 12/24/2022] [Indexed: 06/17/2023]
Abstract
This study looked at optimizing the composition of precursors for yttria nanopowder glycine-nitrate self-propagating high-temperature synthesis (SHS). Based on thermodynamic studies, six different precursor compositions were selected, including with excesses of either oxidant or fuel. The powders from the precursors of all selected compositions were highly dispersed and had specific surface areas ranging from 22 to 57 m2/g. They were consolidated by hot pressing (HP) with lithium-fluoride sintering additive and subsequent hot isostatic pressing (HIP). The 1 mm thick HPed ceramics had transmittance in the range of 74.5% to 80.1% @ 1μm, which was limited by optical inhomogeneity due to incomplete evaporation of the sintering additive. Two-stage HIP significantly improves optical homogeneity of the ceramics. It was shown that an excess of oxidizer in the precursor decreases the powders' agglomeration degree, which forms large pore clusters in the ceramics.
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Affiliation(s)
- Dmitry Permin
- Faculty of Chemistry, N.I. Lobachevsky National Research University, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, 49 Tropinin Str., 603137 Nizhny Novgorod, Russia
| | - Olga Postnikova
- Faculty of Chemistry, N.I. Lobachevsky National Research University, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, 49 Tropinin Str., 603137 Nizhny Novgorod, Russia
| | - Stanislav Balabanov
- Faculty of Chemistry, N.I. Lobachevsky National Research University, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, 49 Tropinin Str., 603137 Nizhny Novgorod, Russia
| | - Alexander Belyaev
- Faculty of Chemistry, N.I. Lobachevsky National Research University, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, 49 Tropinin Str., 603137 Nizhny Novgorod, Russia
| | - Vitaliy Koshkin
- Faculty of Chemistry, N.I. Lobachevsky National Research University, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, 49 Tropinin Str., 603137 Nizhny Novgorod, Russia
| | - Oleg Timofeev
- Faculty of Chemistry, N.I. Lobachevsky National Research University, 23 Gagarin Ave., 603022 Nizhny Novgorod, Russia
- G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, 49 Tropinin Str., 603137 Nizhny Novgorod, Russia
| | - Jiang Li
- Transparent Ceramics Research Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China
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Thermal Conductivity of Yttria-Gadolinia Solid Solution Optical Ceramics in the Temperature Range 50–300 K. INORGANICS 2022. [DOI: 10.3390/inorganics10060078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This study looked at the thermal conductivity of translucent (Y1−xGdx)2O3 (where 0 ≤ x ≤ 1) solid solution ceramics in the temperature range from 50 K to 300 K. The samples were obtained by hot pressing from high-purity nanopowders at 1600 °C, no sintering additives were used. Compositions with cubic syngony (x ≤ 0.7) and a monoclinic one (x ≥ 0.9) were investigated. Furthermore, a dense sample of cubic Gd2O3 with a LiF sintering additive was obtained and its thermal conductivity was determined (k = 11.7 W/(m K) at 300 K). It was shown that in the range of solid solution ceramic compositions 0.2 ≤ x ≤ 0.7, the thermal conductivity was practically unchanged and close to the value k ≈ 5 W/(m K) at 300 K.
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