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通过模压成型和高温烧结制备了不同SiC_P颗粒尺寸(20、50、100和150μm)的预制体,采用高分辨率(~1.0μm)三维X射线断层扫描和三维孔隙网络结构模型,研究了SiC_P颗粒尺寸对预制体孔洞三维特征的影响。结果表明:随着SiC_P颗粒尺寸的增大,淀粉的间隙膨胀作用逐渐减弱,而颗粒堆积间隙逐渐增大。当SiC_P颗粒尺寸由20μm增大到100μm时,截面孔洞形貌更加平齐,面孔隙率均值减小,孔洞体积的空间分布均匀性和连通性都变差,孔洞和喉道的平均尺寸增大,而小尺寸孔喉数量减少,平均孔洞配位数减小;当颗粒尺寸继续增大至150μm时,间隙被更多较小尺寸颗粒填充,且颗粒表面残留网状粘结剂,都大大降低了孔洞体积的空间分布均匀性和连通性,使小尺寸孔喉数量增多,平均孔洞配位数增大。
The preforms with different SiC_P particle sizes (20, 50, 100 and 150μm) were prepared by compression molding and high temperature sintering. High resolution (~ 1.0μm) 3D X-ray tomography and three- Effect of size on 3D features of prefabricated holes. The results show that as the size of SiC_P particles increases, the expansion of starch gradually diminishes while the particle packing gap increases gradually. When the size of SiC_P particles increases from 20μm to 100μm, the cross-sectional pore morphology is more homogeneous and the mean value of surface porosity decreases, the spatial distribution uniformity and connectivity of pore volume become worse, and the average size of pores and throats increases , While the number of small pore throats decreased and the average pore coordination number decreased. When the particle size continued to increase to 150 μm, the gap was filled with more smaller size particles and the residual network binder remained on the particle surface The spatial distribution and connectivity of the pore volume increase the number of small pore throats and increase the average pore coordination number.