Diopside (CaMgSi₂O₆) glass-ceramic, a typical derivative of the pyroxene system, has attracted considerable attentions in the fields of anti-erosion, anti-abrasion, light-emitting diode (LED) packaging, or electric circuit substrate materials because of its high mechanical strength, good physical and chemical stability, as well as remarkable low dielectric coefficient and loss. However, the effect of niobium pentoxide (Nb₂O₅) on the microstructure and property of this technically important glass-ceramic is still not fully understood. Therefore, diopside glass-ceramics with 0 wt%, 0.1 wt%, 0.025 wt%, 0.5 wt%, 1 wt%, 2 wt%, and 4 wt% of Nb₂O₅ were synthesized respectively by the traditional melting method using Bayan Obo mine tailing and fly ash as the main starting materials. The obtained materials were studied by differential scanning calorimetry, X-ray diffractometry, Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, mechanical property, and dielectric property measurements to reveal the effect of Nb₂O₅ on its microstructure and property. The result shows the addition of Nb₂O₅ has a clear effect on increasing the formation of diopside crystals and the crystallization of calcium niobate (Ca₂Nb₂O₇) secondary phase at the intergranular areas between diopside crystals. And this latter microstructural change relates closely with the decrease in the average size of diopside crystals and their morphology changing from the ones resembling chrysanthemum flowers to clusters of roughly round islands. Addition of Nb₂O₅ up to 2 wt% exhibits a near monotonous effect on improving the bending strength. The maximum value of it can reach as high as 236 MPa. The dielectric constant rises from 7 to 9.7 with the increase of Nb₂O₅ addition from 0 to 4 wt%, while the dielectric loss fluctuates within the range of 0.015 to 0.035. The comparison of the results of this study with those of peers showed the crystallization of diopside crystals was more likely enhanced through the mechanism related to the Nb₂O₅-induced phase separation in the base glass rather than the normally reported heterogeneous nuclei mechanism reported for Ferric oxide (Fe₂O₃), chromium trioxide (Cr₂O₃), and titania (TiO₂).

中文翻译：

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五氧化二铌（Nb 2 O 5）对巴彦鄂博矿山尾矿生产透辉石微晶玻璃性能的影响

辉石体系的典型衍生物-透辉石（CaMgSi ₂ O ₆）微晶玻璃在抗腐蚀，抗磨蚀，发光二极管（LED）封装或电路基板材料领域引起了广泛关注具有很高的机械强度，良好的物理和化学稳定性以及低介电系数和低损耗。然而，五氧化_二铌（Nb ₂ O ₅）对这种技术上重要的玻璃陶瓷的微观结构和性能的影响仍未完全清楚。因此，透辉石玻璃陶瓷具有0wt％，0.1wt％，0.025wt％，0.5wt％，1wt％，2wt％和4wt％的Nb ₂ O _5。分别以传统的冶炼方法，以巴彦鄂博矿山尾矿和粉煤灰为主要原料合成。通过差示扫描量热法，X射线衍射法，拉曼光谱，扫描电子显微镜，能量色散X射线光谱，机械性能和介电性能测量研究所得材料，以揭示Nb ₂ O ₅对其微观结构和结构的影响。属性。结果表明，添加Nb ₂ O ₅对增加透辉石晶体的形成和铌酸钙（Ca ₂ Nb ₂ O ₇）透辉石晶体之间的晶间区域的第二相。后者的微观结构变化与透辉石晶体的平均尺寸的减小及其形态的变化密切相关，它们的形态从类似于菊花的花朵变为大致圆形的岛簇。最多2wt％的Nb ₂ O ₅的添加在提高弯曲强度方面表现出近乎单调的效果。它的最大值可高达236 MPa。随着Nb ₂ O ₅的增加，介电常数从7增加到9.7介电损耗在0.015至0.035范围内波动时，添加量为0至4 wt％。这项研究与同行研究结果的比较表明，透辉石晶体的结晶更有可能通过与Nb ₂ O ₅诱导的玻璃中相分离有关的机制而增强，而不是通常报道的异质核机制。氧化铁（Fe ₂ O ₃），三氧化铬（Cr ₂ O ₃）和二氧化钛（TiO ₂）。