C形、中空截面碳化硅纤维的成形工艺研究

Study on Formation of C-shaped and Hollow Silicon Carbide Fibers

以聚碳硅烷 (PCS)为原料 ,经C形喷丝板熔融纺丝制备C形、中空截面PCS原丝后 ,再经不熔化和高温烧成后得到C形、中空截面SiC纤维。文中讨论了纺丝温度、N2 压力和收丝速度对两种PCS纤维当量直径和异形度的影响 ,以及不熔化和烧成工艺对SiC纤维截面形状的影响。结果表明 ,纺丝温度对C形、中空PCS纤维当量直径和异形度影响较大 ;合适的纺丝工艺和不熔化及烧成条件下可以得到高异形度低当量直径的C形。

Polycarbosilane (PCS) was melt spun through C shaped spinneret in N 2 pressure; the C shaped and hollow PCS fibers were thus obtained. The precursor fibers were cured in air, heated to high temperature in N 2 atmosphere under tension; then the C shaped and hollow SiC fibers were prepared. And the effects of spinning temperature, N 2 pressure, take up rate, curing and heating process on effective filament diameters and degree of profile were mainly analyzed. The results showed that the effective filament diameter and degree of profile were significantly affected by spinning temperature; C shaped and hollow cross section SiC fibers with high degree of profile and small effective filament diameter could be prepared under appropriate spinning, curing and heating conditions.