造孔剂含量对多孔BiScO3-PbTiO3高温压电陶瓷性能的影响

为研究造孔剂含量对多孔BiScO3-PbTiO3(记作BS-PT)高温压电陶瓷性能的影响，采用炭黑作为造孔剂，通过传统固相烧结法对不同初始固相体积分数的准同型相界附近的BS-PT/炭黑混合物制备出多孔高温压电陶瓷.利用X射线衍射仪对多孔陶瓷进行物相分析，通过扫描电子显微镜观察样品的新鲜断面和抛光热腐蚀后的表面显微结构，并对其压电、介电和水声性能进行研究.结果表明：制备的不同初始BS-PT体积分数多孔压电陶瓷均为立方钙钛矿相结构，孔隙通道密实化清晰可见，没有显著的缺陷，气孔的形状是长条形的，长度从几微米到几十甚至上百微米不一，气孔之间是孤立的；随着造孔剂炭黑的体积分数从20%增加至50%，气孔率线性地从8.3%增加至22.1%，εr、d33及d31逐渐下降，静水压优值(HFOM)逐渐增大.多孔压电陶瓷的性能强烈依赖于孔隙空间结构, 如气孔率、孔径、孔隙形态及连接方式.
Here, the porous BiScO3-PbTiO3 (BS-PT) high temperature piezoelectric ceramics were prepared using carbon black as the pore-former. The influence of different pore-former ratios on the properties of BS-PT was studied. The microstructure of the porous ceramics was characterized to be pure tetragonal perovskite by using X-ray diffraction and scanning electron microscopy. Properties of the porous BS-PT ceramics, including porosity, piezoelectric coefficient (d33 and d31), dielectric properties (εr) and hydrostatic figure of merit (HFOM) were measured. The ceramics with different initial BS-PT volume fraction showed almost fully dense BS-PT walls without any noticeable defects. Pore has a strip-like shape, with a length ranging from several microns to several hundred microns. As the volume fraction of the pore-former increased from 20% to 50%, porosity linearly increased from 8.3% to 22.1%, whereas, εr, d33 and d31 gradually decreased, and HFOM increased. The properties of porous BS-PT were strongly dependent on their pore configuration, such as porosity, pore size, pore morphology, as well as their connection type.