Materials World Network: Ceramic Composites from Natural and Synthetic Scaffolds

大自然提供了一些复杂但有效的机械强度、韧性、隔热和流体传导材料设计的复杂例子。这些设计可以被复制，以木材为模板生产陶瓷材料。 “生物形态”碳化硅陶瓷可以通过木材的受控热解形成，为含硅液体或气体渗透提供碳支架。硅与碳反应形成碳化硅，其具有复杂的细胞微观结构，让人想起木材。多孔碳化硅结构具有开放通道，为金属的进一步渗透提供了有用的支架，从而形成了一种新型复合材料，可增强机械鲁棒性、导电性或导热性。这项工作的目标是为使用天然支架生产的复合材料建立新的方向。由于碳化硅及其前体碳是用途极其广泛的材料，其性能范围从绝缘到高导电，从坚硬到润滑，因此研究重点是使用碳化硅和碳支架进行复合材料设计。将生物形态复合材料与合成结构的热、电和机械响应进行比较。这项工作的目标有三个：(1) 基于热力学考虑确定最佳合金系统，并开发 SiC/Si 和 C/Cu 生物形态复合材料的加工方法，(2) 表征生物形态复合材料的热、电和机械性能，并将其与合成复合材料进行对比，(3) 使用基于微观结构的有限元分析来预测最佳复合材料微观结构，并了解复杂复合材料微观结构在热、电和机械响应中的行为。该项目是与西班牙塞维利亚大学（加工和微观结构表征）、马德里理工大学（机械性能和建模）以及圣彼得堡约夫物理技术研究所（电、热和弹性性能）合作完成的。 西北大学专注于碳/铜材料、其机械和热性能以及建模。西北大学、塞维利亚大学、马德里理工大学和约夫物理技术研究所之间的合作为学生提供了重要的大学间培训。 由于多孔陶瓷材料在从传感器到燃料电池再到绝缘材料的应用中发挥着如此重要的作用，因此计划合作者共同努力创建一门有关多孔材料的课程。课程材料将通过网络开发和分发以扩大传播。该奖项由国际科学与工程办公室共同资助。

Nature has provided some sophisticated examples of complex, but effective materials design for mechanical strength, toughness, thermal insulation and fluid conduction. These designs can be replicated to produce ceramic materials using wood as a template. "Biomorphic" SiC ceramics can be formed through the controlled pyrolysis of wood to provide a carbon scaffold for infiltration by a silicon-containing liquid or gas. The silicon reacts with the carbon to form SiC with a complex cellular microstructure reminiscent of the wood. The porous SiC structure, with its open channels, provides a useful scaffold for further infiltration by metals resulting in a new class of composite materials for enhanced mechanical robustness, electrical or thermal conductivity. It is the goal of this work to establish new directions in composite materials produced with naturally derived scaffolds. Because silicon carbide and its precursor carbon are extremely versatile materials in which properties can range from insulting to highly conductive, and from hard to lubricious, studies focus on the use of silicon carbide and carbon scaffolds for composite design. Biomorphic composite materials are compared to synthetically derived structures in their thermal, electrical and mechanical response. The objectives of this work are three-fold: (1) To identify optimal alloy systems, based on thermodynamic considerations, and develop processing methodologies for SiC/Si and C/Cu biomorphic composites, (2) To characterize the thermal, electrical and mechanical properties of biomorphic-based composite materials and contrast them with synthetically derived composites, and (3) To use microstructural-based finite element analysis to predict optimal composite microstructures and to understand the behavior of complex composite microstructures in their thermal, electrical and mechanical response. The project is done in conjunction with Universidad de Sevilla (processing and microstructural characterization) and Universidad Politcnica de Madrid (mechanical properties and modeling) in Spain and the Ioffe Physico-Technical Institute (electrical, thermal, and elastic properties) in St. Petersburg. Northwestern focuses on C/Cu materials, their mechanical and thermal properties, and modeling.The collaboration among Northwestern University, Universidad de Seville, Universidad Politcnica de Madrid, and the Ioffe Physico-Technical Institute offers significant inter-university training of students. Since porous ceramic materials play such an important role in applications from sensors to fuel cells to insulation, a joint effort among collaborators to create a course on porous materials is planned. Course materials will be developed and distributed via the web to augment dissemination. This award is co-funded with the Office of International Science and Engineering.