2results about How to "High ceramic yield" patented technology

This invention discloses a silicon carbide fiber precursor polycarbosilane and its preparation method, belonging to the field of polycarbosilane preparation technology. The preparation method of the silicon carbide fiber precursor polycarbosilane includes the following steps: Step 1: Preparing a Grignard reagent; Step 2: Adding an organic alkane to tetrahydrofuran, stirring and mixing, then slowly adding it to the Grignard reagent, stirring and reacting; after the reaction is complete, heating to room temperature, adding a composite organic auxiliary agent, stirring and reacting; after the reaction is complete, quenching the reaction, separating the liquids, washing, and drying to obtain a prepolymer; Step 3: After vacuum distillation of the prepolymer, transferring it to a reaction vessel, heating and polymerizing it under argon atmosphere; after the reaction is complete, adding it to toluene, dissolving, filtering, precipitating, and drying to obtain the silicon carbide fiber precursor polycarbosilane. The polycarbosilane prepared by the above method has excellent thermal stability and high-temperature mechanical properties.

This invention relates to the field of ceramic additives, specifically to an additive and its preparation process for inhibiting high-temperature cracking in ultra-high temperature ceramic precursors. This additive addresses the problem that traditional additives cannot effectively inhibit high-temperature cracking in ceramic precursors. By combining functional nanoparticles, functional filler slurry, and nanofillers, this additive achieves a four-fold synergistic crack inhibition mechanism during the pyrolysis of ultra-high temperature ceramic precursors: physical support framework, chemical reaction compensation for shrinkage, organic phase decomposition to relieve gas stress, and in-situ generation of nanocrystals to pin cracks. This additive exhibits good compatibility with various ceramic precursor systems, requires only a small dosage, and can significantly eliminate macroscopic cracks and reduce volume shrinkage, while simultaneously improving ceramic yield and optimizing microstructure.