【摘要】 本文以粉煤灰、滑石、氧化铝和氧化镁为原料，加入质量分数为0%、0.5%和1.0%的氟化钇，通过高温烧结制备了粉煤灰基堇青石陶瓷样品，研究了氟化钇掺量对样品的物相组成、显微结构及主要性能的影响。结果表明，氟化钇的引入可降低堇青石的生成温度，提高堇青石的物相转化率，显著改善材料的力学性能，同时对热学性能亦有一定积极影响。当氟化钇添加量为0.5%时，样品的综合性能最优。当烧结温度为1 300℃时，XRD未见明显杂质峰，样品的体积密度为2.15 g/cm³,开孔孔隙率为7.49%,吸水率为3.49%,压缩强度为252.27 MPa,经5次热震试验后压缩强度仍然高至204.65 MPa,比热容为0.770～0.931 J/（g·℃）（25～150℃）,热膨胀系数为2.54×10^-6℃^-1（100～800℃）。与不含添加剂的样品相比，添加0.5%氟化钇样品的体积密度增加了5.2%,开孔孔隙率降低了58.6%,吸水率降低了60.6%,而压缩强度增加了4.6倍，比热容增强而热膨胀系数降低。在粉煤灰基堇青石陶瓷的烧结过程中，氟化钇的引入可使其在较低的温度下形成液相，提高元素迁移率，促进晶粒发育完全且具有细化晶粒的明显效果。氟化钇作为一种有效的烧结助剂，微量的添加即可显著改善粉煤灰基堇青石陶瓷的综合性能。本工作拓宽了高效烧结助剂选择范围，可为高质量陶瓷材料的高温烧结提供一定参考。更多还原

【Abstract】 Fly ash-based cordierite ceramics samples were prepared with fly ash, talc, alumina and magnesium oxide, by adding yttrium fluoride（YF₃） with mass fraction of 0%, 0.5% and 1.0%, respectively. The effect of YF₃ on phase composition, microstructure and physical properties of samples were studied. The results show that the introduction of YF₃ reduces formation temperature of cordierite, improves phase conversion rate of cordierite, significantly increases the mechanical properties and has a moderate positive effect on thermal properties of samples. When the YF₃ content is 0.5%, the performance of sample is the best. For the sample with 0.5% YF₃ content, when the sintering temperature is 1 300 ℃, no obvious peak corresponding to any impurity is found in XRD patterns, the bulk density of sample is 2.15 g·cm^-3, the open porosity is 7.49%, the water absorption is 3.49% and the compressive strength is 252.27 MPa. After 5 times heat shock experiments, the compressive strength is still high to 204.65 MPa. The heat capacity is 0.770～0.931 J/（g·℃）（25～150 ℃）, and thermal expansion coefficient is 2.54×10^-6 ℃^-1（100～800 ℃）. The bulk density of sample with 0.5% YF₃ content increases by 5.2%, open porosity decreases by 58.6%, water absorption decreases by 60.6%, compressive strength increases by 4.6 times, heat capacity increases and the thermal expansion coefficient decreases, compared with the sample without additives. In the sintering process of fly ash-based cordierite ceramics, the introduction of YF₃ can form a liquid phase at a lower temperature, improve the mobility of elements, and promote the development of grains and fine grain size. As an effective sintering additive, YF₃ significantly improves the comprehensive properties of fly ash-based cordierite ceramics with a small content. This work broadens the additives range for high quality ceramic materials, which provides reference for excellent materials sintered at high temperature.更多还原