硼酸镁晶须多孔陶瓷的原位固相合成及其性能

Microstructure and properties of porous magnesium borate whisker ceramics with in-situ solid reaction synthesis

采用热分析仪、X线衍射仪（XRD）、扫描电子显微镜（SEM）及力学实验方法,研究碱式碳酸镁和硼酸反应体系的相变过程,研究Mg与B摩尔比和烧成温度对原位固相合成硼酸镁（Mg2B2O5）多孔陶瓷的组织结构、形貌和性能的影响,并探讨Mg2B2O5晶须的生长机制。结果表明：采用碱式碳酸镁和硼酸为原料可以制备出Mg2B2O5晶须多孔陶瓷;在Mg与B摩尔比为1∶1.5和加热温度为900℃条件下,合成多孔陶瓷中Mg2B2O5晶须的直径和长度分别为0.2-0.3μm和4.0-8.0μm;多孔陶瓷的抗压强度可达4.72 MPa。Mg2B2O5晶须生长符合固-液-固生长机制。

The effects of mole ratio of Mg and B,sintering temperature on morphology of the magnesium borate（ Mg2B2O5） whiskers,and the microstructure and mechanical properties of the porous ceramics were investigated by thermal analysis,X-ray diffraction（ XRD）,scanning electron microscopy（ SEM）and uniaxial compression test. Results indicated that the diameters and the lengths of Mg2B2O5 whiskers in the porous ceramics synthesized in-situ by basic magnesium carbonate-H3BO3 mixture were 0. 2-0. 3μm and 4. 0-8. 0 μm,respectively,while the strength of porous ceramics was 4. 72 MPa. The formation mechanism of the Mg2B2O5 whiskers conformed to the solid-liquid-solid（ SLS） growth.