Ge Min, Lv Xiaoxu, Zhang Hao, Yu Shouquan, Lu Zhenxi, Zhang Weigang
State Key Laboratory of Multi-phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
National Key Laboratory of Advanced Composites, Beijing Institute of Aeronautical Materials, Aero Engine Corporation of China, Beijing 100095, China.
Materials (Basel). 2020 May 6;13(9):2142. doi: 10.3390/ma13092142.
Continuous ceramic fiber comprising silicon carbide-zirconium carbide (SiC-ZrC) binary phases was obtained through melt spinning, electron-beam curing and pyrolysis of a pre-ceramic precursor of polyzirconocenecarbosilanes (PZCS). After pyrolysis and heat treatment, ZrC particles with mean diameters of 15-20 nm were formed and homogeneously dispersed in a matrix of fine crystalline β-SiC with an average grain size of 6-10 nm. Concentration of Zr in the fiber varies from 14.88% to 17.45% by mass. Fibers consisting of near-stoichiometric ZrC and SiC with little free carbon can be obtained through pyrolysis decarbonization of the as-cured fiber in hydrogen from room temperature to 1000 °C, and subsequently heat treatment in argon up to 1600 °C for 1 h. High-temperature treatment of these amorphous inorganic fibers leads to crystallization of the binary phases of β-SiC and ZrC. The removal of free carbon under hydrogen results in more rapid growth of β-SiC and ZrC crystals, in which obvious aggregation of the dispersed ZrC particles among the continuous β-SiC matrix can be ascribed to a fast migration of Zr cation.
通过对聚锆碳硅烷（PZCS）的陶瓷前驱体进行熔体纺丝、电子束固化和热解，获得了包含碳化硅-碳化锆（SiC-ZrC）二元相的连续陶瓷纤维。热解和热处理后，形成了平均直径为15-20nm的ZrC颗粒，并均匀分散在平均晶粒尺寸为6-10nm的细晶β-SiC基体中。纤维中Zr的质量浓度在14.88%至17.45%之间变化。通过将固化后的纤维在氢气中从室温至1000°C进行热解脱碳，随后在氩气中于1600°C热处理1小时，可以获得由接近化学计量比的ZrC和SiC组成且几乎不含游离碳的纤维。对这些非晶态无机纤维进行高温处理会导致β-SiC和ZrC二元相结晶。在氢气气氛下除去游离碳会使β-SiC和ZrC晶体生长更快，其中连续β-SiC基体中分散的ZrC颗粒明显聚集可归因于Zr阳离子的快速迁移。
