SBIR Phase I: Net Shape, SiC-Toughened Mollybdenum Disilicide Composites

9860602 第一阶段小企业创新研究（SBIR）项目旨在定制和开发（纤维）增强的MOSi 2复合材料，其强度和韧性可达到非常高的温度（~ 1400 ℃）。MOSi 2基质将形成并用受控量的SiC纤维（连续或短切）增强，并且复合材料在一个步骤中致密化。SiC增强材料将为复合材料提供结构强度和韧性，而不会增加其重量。致密化将在将Mo、Si和C的元素混合物的SHS（燃烧合成）与HIP（电固结）相结合的单步工艺中完成。连续或短切SiC纤维的原位增强将通过Si和C在Mo和Si之间的SHS反应的绝热温度或低于该绝热温度下的反应而发生。该工艺的近净成形能力通过使用用于渗透的C纤维预制件而增强。二硅化钼（MOSi 2）具有吸引人的耐热性、抗氧化性和耐腐蚀性，但结构较弱。用机械性能优良的上级第二相材料增强，使得MoSi 2基复合材料成为有用应用的重要候选材料，如果该复合材料可以经济地加工成净形状的话。 SiC增韧的MOSi 2复合材料可作为加热元件、燃烧和燃烧器装置以及熔融金属过滤器实现直接商业用途。未来的应用包括用于航空和燃气涡轮机发动机部件、热交换器、废物焚烧炉和热气过滤器。其他先进的应用包括能量存储设备，如超级电容器。

9860602 This Phase I Small Business Innovation Research (SBIR) project aims to tailor and develop (fiber)-reinforced MOSi2 composites with enhanced strength and toughness up to very high temperatures (~1400C). The MOSi2 matrix will be formed and reinforced with controlled amounts of SiC fibers (continuous or chopped), and the composite densified in one step. The SiC reinforcement will provide structural strength and toughness to the composite without adding to its weight. Densification will be accomplished in a single step process that combines SHS (combustion synthesis) of elemental mixtures of Mo, Si, and C with HIPing (electro-consolidation). In-situ reinforcement with continuous or chopped SiC fibers will take place through reaction of Si and C at or below the adiabatic temperatures of SHS reaction between Mo and Si. Near-net shape capability of the process is enhanced by the use of C fiber preforms for infiltration. Molybdenum disilicide (MOSi2) has attractive thermal, oxidation, and corrosion resistance properties but is weak structurally. Reinforcement with a mechanically superior second phase material makes MoSi2-based composites serious candidates for useful applications, if the composites can be processed to net shape and economically. Immediate commercial use of the SiC-toughened MOSi2 composites can be realized as heating elements, combustion and burner rigs, and molten metal filters. Future applications include uses for aviation and gas turbine engine components, heat exchangers, waste incinerators, and hot gas filters. Other advanced applications include energy storage devices such as ultracapacitors.