摘要
利用同步辐射CT(SR-CT)技术,在氮化硅陶瓷样品烧结过程中对其进行实时投影成像,并应用滤波反投影算法和数字图像处理技术,得到了样品在整个烧结过程中内部微结构演化的二维和三维重建图像,实现了对陶瓷固相烧结过程实时、无损的观测.通过重建图像清晰观测到了陶瓷样品在烧结三个阶段中颗粒接触、烧结颈形成、晶粒和气孔长大、气孔球化并收缩等烧结现象;统计了样品在不同烧结时刻的孔隙率,得到了孔隙率随烧结时间对数的变化曲线,并根据曲线分析了样品在不同烧结时刻致密化速率的变化,得到了烧结中期孔隙率和时间对数的线性关系.实验的结果和现有烧结理论相吻合,并为进一步完善烧结理论提供了有效的实验数据.
Microstructure-evolution of the silicon nitride ceramics sample during sintering process was investigated by a synchrotron radiation X-ray computed tomography （SR-CT） technique. The projection images of the sample were obtained during the sintering process in real-time. 2-D and 3-D reconstructed images were obtained by treating the projection images of different sintering periods with filter back projection arithmetic and digital image processing methods. From the reconstructed images, three sintering stages of the silicon nitride ceramic sample were clearly distinguished and several sintering phenomena during the sintering process such as grain contact, sintering neck growth and pore spheroidization were observed. Densification rate of sintering process was analyzed from the porosity-time logarithm curve, which was obtained from the reconstructed images of silicon nit-ride ceramic sample at different sintering time. The three sintering stages and linear relationship between porosity and time logarithm in the middle stage of sintering which has already been described in the traditional sintering theories were clearly observed from the porosity-time logarithm curve. The experiment results are in concordance with the sintering theory and provide effective experimental data for further analysis of the sintering process and the mechanical characteristics of ceramics.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2009年第11期1205-1210,共6页
Acta Chimica Sinica
基金
国家自然科学基金(No.10732080)
北京同步辐射实验室(BSRF)基金资助项目
关键词
材料检测与分析技术
固相烧结
同步辐射CT
氮化硅陶瓷
微结构演化
analysis and testing technology of materials
sintering
synchrotron radiation X-ray computed tomography
silicon nitride ceramic
microstructure evolution
