Permin Dmitry, Postnikova Olga, Balabanov Stanislav, Belyaev Alexander, Koshkin Vitaliy, Timofeev Oleg, Li Jiang
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.
Materials (Basel). 2022 Dec 27;16(1):260. doi: 10.3390/ma16010260.
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 m/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.
本研究着眼于优化用于氧化钇纳米粉末甘氨酸 - 硝酸盐自蔓延高温合成（SHS）的前驱体组成。基于热力学研究，选择了六种不同的前驱体组成，包括氧化剂或燃料过量的情况。所有选定组成的前驱体制备的粉末高度分散，比表面积范围为22至57 m/g。它们通过添加氟化锂烧结添加剂进行热压（HP）并随后进行热等静压（HIP）固结。1毫米厚的热压陶瓷在1μm处的透过率范围为74.5%至80.1%，这受到烧结添加剂未完全蒸发导致的光学不均匀性的限制。两阶段热等静压显著提高了陶瓷的光学均匀性。结果表明，前驱体中氧化剂过量会降低粉末的团聚程度，这会在陶瓷中形成大的气孔簇。
