颗粒尺寸对SiC_P预制体孔洞三维特征的影响

发布时间：2018-11-23 19:01

【摘要】：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。
[Abstract]:Preforms with different SiC_P particle sizes (2050 100 and 150 渭 m) were prepared by moulding and high temperature sintering. High resolution (~ 1.0 渭 m) 3D X-ray tomography and 3D pore network model were used. The effect of SiC_P particle size on the three dimensional characteristics of prefabricated voids was studied. The results showed that with the increase of SiC_P particle size, the gap expansion of starch gradually weakened, while the gap of granule accumulation gradually increased. When the particle size of SiC_P is increased from 20 渭 m to 100 渭 m, the pore morphology of the cross section becomes more uniform, the average surface porosity decreases, the spatial distribution uniformity and connectivity of the pore volume become poor, and the average size of the pore and throat increases. However, the number of small pore throats decreased and the average coordination number of holes decreased. When the particle size continues to increase to 150 渭 m, the gap is filled with more smaller particles, and the residual mesh binder on the particle surface greatly reduces the spatial distribution uniformity and connectivity of the pore volume and increases the number of small pore throats. The average pore coordination number increases.
【作者单位】：华南理工大学国家金属材料近净成形工程技术研究中心;
【基金】：国家自然科学基金(51375171)
【分类号】：TB333

【相似文献】