Characterization of Nax(Ca/Sr)1-2xNdxWO4 complex tungstates fine-grained ceramics obtained by Spark Plasma Sintering
| Autor: | S. V. Shotin, A. V. Nokhrin, O. A. Belkin, E. A. Potanina, N. V. Sakharov, M. G. Tokarev, A. I. Orlova, Maksim Boldin, V. N. Chuvil’deev, A.Yu. Zelenov |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Coprecipitation Process Chemistry and Technology Analytical chemistry Sintering Spark plasma sintering 02 engineering and technology Activation energy 021001 nanoscience & nanotechnology 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry.chemical_compound Grain growth Tungstate chemistry 0103 physical sciences Materials Chemistry Ceramics and Composites Grain boundary diffusion coefficient Grain boundary 0210 nano-technology |
| Zdroj: | Ceramics International. 44:4033-4044 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2017.11.199 |
| Popis: | Mineral-like matrix Na x (Ca/Sr) 1-2x Nd x WO 4 ( x = 0, 0.1 and 0.2) for radwaste is proposed. Powder samples of complex tungstates have been synthesized by coprecipitation from aqueous solutions of Na, Ca, Sr, Nd salts. Crystallographic characteristics of compounds have been calculated and a monotonous change observed in them along with some x value changes. Monophasic ceramics with high relative density (97–100%) from these powders have been obtained through Spark Plasma Sintering (SPS). SPS of tungstates has been shown to occur in multiple stages, with the sintering kinetics at the final stage of sealing controlled by diffusion both in the crystal lattice and along grain boundaries. Activation energies have been determined for sintering of tungstates at different x values. The reduced activation energy of sintering at the third heating stage (at high temperatures) could be ascribed to the grain growth. |
| Databáze: | OpenAIRE |
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