New class of funCtionAl silicon caRBOnitride-based ceramic FIBErs from oRganometal compound-modified polySilazanes

非氧化物陶瓷纤维被广泛应用于陶瓷基复合材料的增强。尽管在过去的几年里，人们在开发新的非氧化物陶瓷纤维方面做出了相当大的努力，但它们在工业级上的使用仅限于碳化硅(SiC)纤维。但碳化硅纤维非常昂贵(从1.5到10千欧元/公斤)，这取决于纤维的质量，主要是因为生产由日本公司主导，没有其他国家的替代产品。为了降低纤维的成本并在这一主题上具有竞争力，本项目建议动员欧洲学术研究人员的活动和资源，特别是来自法国和德国的研究人员。本项目涉及一种具有附加功能的新型高性价比聚合物衍生非氧化物陶瓷纤维的设计、加工和性能研究。建议的材料有望用作具有电和磁性能的热结构应用的增强材料。为了满足上述应用的要求，获得的纤维需要结合在侵蚀性和恶劣环境中的耐用性，同时实现功能特性，如导电性和磁性。这些性能可以通过金属-有机化合物对(Si-(B/Al)-C-N)聚合物的改性来实现，从而导致功能纳米相的原位生长，同时在热解过程中形成相应的陶瓷SiCN(B/Al)基质。为了达到我们的目标，该项目被分为五个相互关联的科学任务。第一个任务(TA1)是通过核磁共振、傅立叶变换红外光谱、相对分子质量测量和元素分析来合成和表征金属修饰的陶瓷前驱体聚合物。第二个任务(TA2)是关于聚合物纤维的熔融纺丝和固化，通过对合成的陶瓷前驱体聚合物的流变学研究来优化纺丝工艺。任务3(TA3)的重点是将在TA2中制备的固化聚合物纤维转化为所需的含有金属的功能化陶瓷纤维。将通过FTIR、TG-GC/MS和固体核磁共振对聚合物到陶瓷的转化进行详细的研究。任务4(Ta4)致力于陶瓷纤维的表征，涉及含金属的SiCN(B/Al)纤维的机械和(纳米)结构特性以及功能，特别是它们的电和磁性能。TA5研究了陶瓷纤维相变的过程建模。

Non-oxide ceramic fibers have been widely used for the reinforcement of ceramic matrix composites (CMCs). Despite considerable efforts to develop new non-oxide ceramic fibers in the last few years, their use at industrial level exclusively concern silicon carbide (SiC) fibers. But SiC fibers are very expensive (from 1.5 to 10 kEuro/kg) depending on the quality of the fibers, mainly because the production is dominated by companies from Japan with no alternative products from other countries. To reduce the costs of the fibers and to be competitive on this topic, a mobilization of activities and resources of the academic European researchers, especially from France and Germany, is proposed in the present project. This project concerns the design, processing and investigation of the properties of a new class of cost-effective polymer derived non-oxide ceramic fibers with additional functional properties. The proposed materials are expected to be used as reinforcement for thermostructural applications with electrical and magnetic properties. To meet the requirements for the applications mentioned above the obtained fibers need to combine durability in aggressive and harsh environments while achieving functional properties, such as electrical conductivity and magnetic properties. These properties can be achieved through the modification of (Si-(B/Al)-C-N) polymers with metal-organic compounds, leading to the in-situ growth of the functional nanophase simultaneously with the formation of the respective ceramic SiCN(B/Al) matrix during pyrolysis. To reach our objectives, the project is divided into five interconnected scientific tasks. The first task (Ta1) is focused on the synthesis and characterization (through NMR, FTIR, molecular weight measurements and elemental analyses) of the metal-modified preceramic polymers. The second task (Ta2) deals with the melt-spinning and curing of the polymer fibers, as the optimization of the spinning process by means of rheological investigation of the synthesized preceramic polymers. Task 3 (Ta3) is focused on the conversion of the cured polymer fibers prepared in Ta2 into the desired metal containing functionalized ceramic fibers. Detailed investigation of the polymer-to-ceramic conversion will be achieved through FTIR, TG-GC/MS and solid-state NMR. Task 4 (Ta4) is dedicated to the characterization of ceramic fibers, concerning the mechanical and (nano)structural properties and the functionalities of the metal-containing SiCN(B/Al) fibers, in particular their electrical and magnetic properties. Ta5 deals with the process modeling of the ceramic fiber transformation.