The effect of LiF on the densification and mechanical properties of hot-pressed Dy-a-sialon ceramics was studied. Comparatively, without LiF as sintering additive, the pure Dy-a-sialon ceramic should be sintered at 1...The effect of LiF on the densification and mechanical properties of hot-pressed Dy-a-sialon ceramics was studied. Comparatively, without LiF as sintering additive, the pure Dy-a-sialon ceramic should be sintered at 1750℃. When LiF is used, the sintering temperature of the Dy-a-sialon is greatly lowered to 1500 ~ 1650℃. Obviously, the addition of LiF has a strong effect on the improvement in densification. Meanwhile, the resultant Dy-a-sialon has no significant changes in the mechanical properties.展开更多
Nitrogen-rich Ca-α-sialon： Eu2＋ phosphors with saturated calcium solubility are synthesized through a solid- state reaction （SSR） at 2173 K with stable alloy and nitride as the starting materials. The Ca1.83-1.sx...Nitrogen-rich Ca-α-sialon： Eu2＋ phosphors with saturated calcium solubility are synthesized through a solid- state reaction （SSR） at 2173 K with stable alloy and nitride as the starting materials. The Ca1.83-1.sxSi8.34 A13.66 Ox N16-x： xEu phosphors have intensive orange emissions, whose peaks are located at approximately 585 600 nm, and the emission wavelengths tend to shift toward the red region when the Eu concentrations increase from 0.5% to 18% （mole percentage）. When the Eu concentration is equal to 9%, the phosphors suffer from concentration quenching. The low-temperature photoluminescence properties indicate that Cal.aa-l.5xSi8.34Ala.66OzN16-x： xEu phosphors show ex- cellent thermal quenching. The crystal structures of Cal.83-1.5xSis.34A13.660xN16-x： xEu are also investigated, and are found to have nitrogen-rich compositions with saturated calcium cations at the interstitial sites of the α-sialons. In addition, tile influencing factors of α-sialons with different compositions on the crystal lattice are discussed in detail.展开更多
文摘The effect of LiF on the densification and mechanical properties of hot-pressed Dy-a-sialon ceramics was studied. Comparatively, without LiF as sintering additive, the pure Dy-a-sialon ceramic should be sintered at 1750℃. When LiF is used, the sintering temperature of the Dy-a-sialon is greatly lowered to 1500 ~ 1650℃. Obviously, the addition of LiF has a strong effect on the improvement in densification. Meanwhile, the resultant Dy-a-sialon has no significant changes in the mechanical properties.
基金National Natural Science Foundation of China(Nos.U2037601,51821001)Key Basic Research Project of the National Basic Strengthening Plan,China(No.2022-xxxx-ZD-093-xx)。
基金Project supported by the National Natural Science Foundation of China (Grant No. 90922027)the National High Technology Research and Development Program of China (Grant No. 2009AA03Z432)the Doctoral Fund of Ministry of China (Grant No. 20100006110011)
文摘Nitrogen-rich Ca-α-sialon： Eu2＋ phosphors with saturated calcium solubility are synthesized through a solid- state reaction （SSR） at 2173 K with stable alloy and nitride as the starting materials. The Ca1.83-1.sxSi8.34 A13.66 Ox N16-x： xEu phosphors have intensive orange emissions, whose peaks are located at approximately 585 600 nm, and the emission wavelengths tend to shift toward the red region when the Eu concentrations increase from 0.5% to 18% （mole percentage）. When the Eu concentration is equal to 9%, the phosphors suffer from concentration quenching. The low-temperature photoluminescence properties indicate that Cal.aa-l.5xSi8.34Ala.66OzN16-x： xEu phosphors show ex- cellent thermal quenching. The crystal structures of Cal.83-1.5xSis.34A13.660xN16-x： xEu are also investigated, and are found to have nitrogen-rich compositions with saturated calcium cations at the interstitial sites of the α-sialons. In addition, tile influencing factors of α-sialons with different compositions on the crystal lattice are discussed in detail.
