Details

Autor(en) / Beteiligte

• Karaeva, M E
• Savinykh, D O
• Orlova, A I
• Khainakov, S A
• Nokhrin, A V
• Boldin, M S
• Garcia-Granda, S
• Murashov, A A
• Chuvil'deev, V N
• Yunin, P A
• Nazarov, A A
• Tabachkova, N Y

Titel

(Na, Zr) and (Ca, Zr) Phosphate-Molybdates and Phosphate-Tungstates: I-Synthesis, Sintering and Characterization

Ist Teil von

• Materials, 2023-01, Vol.16 (3), p.990

Ort / Verlag

Switzerland: MDPI AG

Erscheinungsjahr

2023

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Submicron-grade powders of Na Zr (PO ) (XO ) compounds (hereafter referred to as NZP) and Ca Zr (PO ) (XO ) compounds (hereafter, CZP), X = Mo, W (0 ≤ x ≤ 0.5) were obtained by sol-gel synthesis. The compounds obtained were studied by X-ray diffraction phase analysis and electron microscopy. An increase in the W or Mo contents was shown to result in an increase in the unit cell volume of the NZP and CZP crystal lattices and in a decrease in the coherent scattering region sizes. Thermal expansion behavior at high temperatures of synthesized NZP and CZP compounds has been investigated. The dependencies of the parameters and on the heating temperature, as well as the temperature dependence of the crystal lattice unit cell volume in the range from the room temperature up to 800 °C, were obtained. The dependencies of the average thermal expansion coefficient (α ) and of the volume coefficient (β) on the W and Mo contents in the compositions of NZP and CZP compounds were studied. Ceramics Na Zr (PO ) (XO ) with relatively high density (more than 97.5%) were produced by spark plasma sintering (SPS). The increase in the W or Mo contents in the ceramics leads to an increase in the relative density of NZP and to a decrease of the optimum sintering temperature. The mean grain size in the NZP ceramics decreases with increasing W or Mo contents. The study of strength characteristics has revealed that the hardness of the NZP ceramics is greater than 5 GPa, and that the minimum fracture toughness factor was 1 MPa·m .