烧结助剂添加方式对AIN陶瓷力学性能的影响

摘要

通过直接添加与原位生成两种方式引入Y2O3作为烧结助剂，热压烧结制备了A1N陶瓷；研究了添加方式及添加量对AlN陶瓷显微结构和力学性能的影响。结果表明：原位生成烧结助剂的方式更有利于A1N陶瓷的致密化，特别是当原位生成的YzO。质量分数为2％时，AlN陶瓷的相对密度达到99．0％，硬度为15．39GPa，抗弯强度为383．0MPa，均高于直接添加Y20。的；同时可获得晶形完整、第二相含量少且大部分位于三叉晶界、晶粒间面一面接触的显微结构；随着原位生成烧结助剂添加量的增多，陶瓷的相对密度下降，在A1N晶界处%A1N ceramics were fabricated by hot-pressing with Y203 as sintering additive added by direct addition and in-situ formation. The effects of adding method and amount of sintering additive on microstructure and mechanical properties of A1N ceramics were investigated. The results show that the sintering additive added by insitu formation was more beneficial to densification of A1N ceramics, and particularly, when Y2 03 was added by insitu formation and reached 2wt%, the relative density, hardness and flexural strength could reach up to 99.0%, 15.39 GPa and 383. 0 MPa, respectively, higher than those when Y203 was added directly. At the same time an integrated-shaped microstructure with low content of secondary phase, which mainly distributed at trigeminal grain boundaries, and with surface contact between grains was generated. However, with the increase of adding amount of the sintering additive added by in-situ formation, the relative density, hardness and flexural strength of A1N ceramics decreased due to the large amount of secondary phase at grain boundaries.