Gong Dexiang, Zhou Yi, Shi Yunwei, He Qianglong
School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China.
Hubei Longzhong Laboratory, Xiangyang 441000, China.
Materials (Basel). 2025 Jul 30;18(15):3573. doi: 10.3390/ma18153573.
Textured SiN/BN composite ceramics were successfully fabricated using two-step sintering, combining pseudo-hot isostatic pressing (PHIP) and gas pressure sintering. The grain size of h-BN platelets had a significant influence on densification and mechanical and thermal properties. With an increase in h-BN grain size, the volume density of the composite ceramics gradually decreased, while flexural strength gradually increased. Meanwhile, larger h-BN platelets were more likely to trigger toughening mechanisms like large-angle deflection and greatly increase fracture toughness. Through proper selection of h-BN grain size, textured ceramics, with the addition of h-BN platelets of 1-2 μm, showed high thermal conductivity (∼92 W∙m∙K) and reliable mechanical properties (∼540 MPa, ∼7.5 MPa∙m, ∼11.1 GPa). Therefore, texture control is an effective means of improving the overall performance of ceramic materials. Novel textured composite ceramics thus have great potential in large-scale fabrication and directional heat dissipation applications.
采用两步烧结法，结合准热等静压（PHIP）和气压烧结，成功制备了织构化SiN/BN复合陶瓷。h-BN片晶的晶粒尺寸对致密化以及力学和热性能有显著影响。随着h-BN晶粒尺寸的增加，复合陶瓷的体积密度逐渐降低，而抗弯强度逐渐增加。同时，较大的h-BN片晶更有可能引发大角度偏转等增韧机制，并显著提高断裂韧性。通过适当选择h-BN晶粒尺寸，添加1-2μm的h-BN片晶的织构化陶瓷表现出高导热率（约92W∙m∙K）和可靠的力学性能（约540MPa、约7.5MPa∙m、约11.1GPa）。因此，织构控制是提高陶瓷材料整体性能的有效手段。新型织构化复合陶瓷在大规模制造和定向散热应用中具有巨大潜力。
