Hexagonal boron nitride (h-BN) composite ceramics were prepared by hot pressing with the addition of Y2O3 and AlN. The effects of different Y2O3–AlN contents on microstructural evolution, mechanical properties and thermal diffusion coefficients of h-BN composite ceramics were investigated. The results indicate that Y2O3–AlN forms a liquid phase during the sintering process, achieving a good wettability with h-BN grains. In pure h-BN ceramic and h-BN composite ceramic with 40 wt% Y2O3–AlN, the h-BN grains grow well when controlled through solid-phase and liquid-phase diffusion, respectively. With the increase in Y2O3–AlN content, mechanical properties and thermal diffusion coefficients of h-BN composite ceramics first decrease and then increase, and the properties of h-BN composite ceramic with 10 wt% Y2O3–AlN are the inflection points. Such properties are highly related to the phase compositions, porosity and microstructure.

中文翻译：

---

液相烧结添加Y2O3-AlN的h-BN复合陶瓷的显微组织演变和力学性能

加入Y2O3和AlN，通过热压制备六方氮化硼(h-BN)复合陶瓷。研究了不同 Y2O3-AlN 含量对 h-BN 复合陶瓷显微组织演变、力学性能和热扩散系数的影响。结果表明，Y2O3-AlN 在烧结过程中形成液相，与 h-BN 晶粒具有良好的润湿性。在纯 h-BN 陶瓷和含有 40 wt% Y2O3–AlN 的 h-BN 复合陶瓷中，h-BN 晶粒在分别通过固相和液相扩散控制时生长良好。随着Y2O3-AlN含量的增加，h-BN复合陶瓷的力学性能和热扩散系数先降低后升高，其中10wt%Y2O3-AlN的h-BN复合陶瓷的性能是拐点。