Structural evolution and associated properties on conversion from Si-C-O-Al ceramic fibers to Si-C-Al fibers by sintering

摘要: Ceramic fibers with the Si-C-O-Al composition were prepared by melt-spinning of polyaluminocarbosilane (PACS), initial curing in air and then thermal curing, before finally being pyrolyzed at 1300 °C. The ceramic so-obtained sintered 1800 °C argon to produce Si-C-Al as a super high temperature-resistant reinforcement. When fibers, structural evolution associated properties studied comparison PCS-derived Si-C-O respect tensile strength, creep resistance, electrical resistivity, morphology, crystalline grain size using 29Si MAS NMR, 13C AES, XRD SEM. had low resistance because they contained levels silicon oxycarbide, poorly organized SiC grains nanometer level free carbon. resistivity the Si-C-O-Al was due oxycarbide. However, strongly resistant oxycarbide structure, well-organized crystallized content lower absence is responsible for their strength retention temperature.