【摘要】 热压烧结制备了ＳｉＯ２ － ＡｌＮ 复合材料． 研究了第二相ＡｌＮ 的引入量和热压温度对ＳｉＯ２ － ＡｌＮ 复合材料力学性能、介电性能和热学性能的影响． 结果说明，第二相ＡｌＮ 的引入有利于ＳｉＯ２ 基复合材料力学性能的提高；３０％ （ 体积分数）ＡｌＮ－ ＳｉＯ２复合材料于１ ４００ ℃下烧结后抗弯强度和断裂韧性分别为２００ ＭＰａ 和２ ．９６ ＭＰａ·ｍ１／２ ． ＸＲＤ 分析证实直至１ ４００ ℃ＡｌＮ与ＳｉＯ２ 间未发生反应，两者有良好的化学相容性；ＳｉＯ２ － ＡｌＮ 复合材料的介电常数和介电损耗随热压温度和第二相ＡｌＮ 的引入量有规律地变化；ＳｉＯ２ － ＡｌＮ 复合材料抗热震性取决于材料内的热应力．ＳｉＯ２ － ＡｌＮ 复合材料在经受热冲击后抗弯强度在ΔＴ＞ ６００ ℃时迅速下降．更多还原

【Abstract】 SiO 2-AlN composites were prepared by hot_pressing process. The relationship among phase composition, microstructure and physical properties was studied. Mechanical properties of SiO 2 matrix composites could be greatly improved after introducing AlN particles. Flexural strength and fracture toughness of the composites with 30%(in volume) AlN sintered at 1 400 ℃ reached 200 MPa and 2.96 MPa·m 1/2 respectively. XRD patterns show that, up to 1 400 ℃, no chemical reaction occurs between SiO 2 and AlN, indicating that SiO 2 has excellent chemical compatibility with AlN. The dielectric properties of SiO 2-AlN composites change regularly with hot_pressing temperature and the content of AlN particles. Thermal shock resistance of SiO 2-AlN composites mainly depends on thermal stress in the body of the composites. Residual flexural strength of SiO 2-AlN composites decreases abruptly above Δ T =600 ℃ because of the mismatch of thermal expansion coefficient between SiO 2 matrix and AlN particles.更多还原