The effect of silicon particle size on the β-phase ratio, microstructure and the flexural strength of porous sintered reaction-bonded silicon nitride(SRBSN) was systematically investigated. Six kinds of raw powders containing Yb₂O₃ addtive (5, 10 wt%), prepared with different particle size distribution, were prepared by planetary ball-milling duration of 0, 3, 24 h. The behavior of α-to-β phase transformation of Si₃N₄ sintered at 1650 °C and 1750 °C, was found to be in good relation with SiO₂ molar ratio over all the oxide additives. High flexural strength of SRBSN over 400 MPa was obtained when the amount of SiO₂ was less than 0.7 owing to having the rod-like β-particles. Otherwise, the flexural strength of SRBSN became lower due to major occurrence of the equiaxed β-particles. This significant difference was considered to be caused from the seeding effect of β-ratio of RBSN samples as well as the different solubility of nitrogen element in the eutectic liquid phase.

系统研究了硅粒径对多孔烧结反应键合氮化硅(SRBSN)的β相比、微观结构和弯曲强度的影响。采用行星式球磨时间为0、3、24 h制备了6种不同粒径分布的含Yb ₂ O ₃添加剂(5、10 wt%)的原料粉。发现在 1650 °C 和 1750 °C 下烧结的 Si ₃ N ₄的 α-β 相变行为与所有氧化物添加剂的SiO ₂摩尔比有良好的关系。当SiO ₂的用量增加时，SRBSN 的抗弯强度超过 400 MPa由于具有棒状 β 粒子，因此小于 0.7。否则，由于等轴β-粒子的主要出现，SRBSN 的弯曲强度降低。这种显着差异被认为是由于 RBSN 样品的 β 比的种子效应以及氮元素在共晶液相中的不同溶解度造成的。