Wei Qingxin, Liu Yang, Le Huirong
The Future Lab, Tsinghua University, Beijing 100084, China.
Materials (Basel). 2022 Jun 13;15(12):4185. doi: 10.3390/ma15124185.
This article investigates several important properties, such as thermal resistance, mechanical properties, and phase evolution, of geopolymer ceramics reinforced with mullite fibers. This particular fiber reinforcing geopolymer composites was prepared from kaolinite and mullite fibers with phosphoric acid as activator. X-ray diffraction (XRD), thermogravimetry and differential scanning calorimetry, Fourier-transform infrared spectroscopy, and scanning electron microscopy were used to determine the phase evolution and strengthening mechanisms. With the addition of mullite fibers, the mechanical properties increased by at least 20%. The optimum flexural strength exceeded 13 MPa. It was found that mullite fibers had desirable interface bonding with this type of geopolymer, promoting both crack deflection and fiber pullout strengthening mechanisms. This was correlated with a significant strengthening effect of the fibers. The linear shrinkage after heat treatment at 1150 °C~1550 °C was investigated and correlated with XRD analyses. The addition of mullite fibers reduced the linear shrinkage significantly up to 1350 °C. The large linear shrinkage above 1450 °C was correlated with the decomposition and melting of the AlPO phase.
本文研究了莫来石纤维增强地质聚合物陶瓷的几种重要性能，如热阻、力学性能和相演变。这种特殊的纤维增强地质聚合物复合材料由高岭土和莫来石纤维制备而成，以磷酸作为活化剂。采用X射线衍射（XRD）、热重分析和差示扫描量热法、傅里叶变换红外光谱以及扫描电子显微镜来确定相演变和增强机制。随着莫来石纤维的添加，力学性能至少提高了20%。最佳抗弯强度超过13MPa。研究发现，莫来石纤维与这种类型的地质聚合物具有良好的界面结合，促进了裂纹偏转和纤维拔出增强机制。这与纤维显著的增强效果相关。研究了在1150℃至1550℃热处理后的线性收缩，并与XRD分析相关联。添加莫来石纤维显著降低了直至1350℃的线性收缩。1450℃以上的大线性收缩与AlPO相的分解和熔化有关。
