Oxide Fiber Composites with three dimensional fiber architectures

具有三维纤维结构的氧化物纤维复合材料

• 批准号: 265438709
• 负责人: Professor Dr.-Ing. Thomas Gries
• 金额: --
• 依托单位: Lehrstuhl für Keramische Werkstoffe
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/265438709?language=en
• 关键词: Oxide; Fiber; Composites; three; dimensional

Structural materials for operation temperatures above 1000 °C in corrosive atmospheres are key elements for developments in energy conversion, transportation and metallurgy. For these applications, oxide fiber composites (OFC) are predestined. CMC are chemically stable and resistant in oxidizing environment. At high temperatures and large temperature gradients CMC show damage-tolerant fracture behaviour. They have a density of less than 3 g/cm³ and mass-specific mechanical properties that exceed those of metallic superalloys. However, there are still significant deficits in the production of CMC.Currently two concepts are investigated to realize damage-tolerant fracture behaviour of OFC. In the first concept a weak fiber-matrix bonding is set low by a fiber coating. However, often the long-term temperature resistance as well as to the homogeneity of the fiber coating is insufficient. The second concept is the so called weak matrix system. The weak matrix decouples the fiber filaments mechanically and enables the damage tolerant fracture behaviour. The drawback of the weak matrix concept is the low interlaminar strength compared to composites with fiber-coating. To overcome this problem, the manufacturing of a three-dimensional fiber architecture and an adjusted matrix design is the topic of this research project. That is why in the first time a new oxide fiber composite material can be used in structural application like gas turbines, heat exchangers and in medical engineering.The only textile manufacturing process for the preparation of such structures is the 3D-Braiding. The adaptation of the 3D braiding for the processing of the extremely brittle ceramic fibres as well as the modification of the ceramic matrix towards lower shrinkage is the focus of this project. This research project will demonstrate that the manufacturing of a three-dimensional reinforced CMC structure is possible, and that the mechanical properties are superior. Of particular interest is the correlation between the reinforcement in the z-axis and the shear strength. Overall, this work provides important concepts and conclusions in the fiber processing and manufacturing of OFC.

在腐蚀性环境中工作温度高于1000 °C的结构材料是能源转换、运输和冶金发展的关键要素。对于这些应用，氧化物纤维复合材料（OFC）是注定的。CMC在氧化环境中具有化学稳定性和耐受性。 在高温和大的温度梯度下，CMC显示出损伤容限断裂行为。它们的密度小于3 g/cm³，质量比机械性能超过金属高温合金。然而，在CMC的生产中仍然存在显著的缺陷。目前，两个概念的研究，以实现OFC的损伤容限断裂行为。在第一个概念中，通过纤维涂层降低了弱的纤维-基质结合。然而，光纤涂层的长期耐温性以及均匀性通常不足。第二个概念是所谓的弱矩阵系统。弱基体使纤维丝机械地缠结，并使损伤容限断裂行为成为可能。弱基体概念的缺点是与具有纤维涂层的复合材料相比层间强度低。为了克服这个问题，制造一个三维的纤维结构和调整矩阵设计是本研究项目的主题。这就是为什么一种新型氧化物纤维复合材料首次可以用于燃气轮机、热交换器和医疗工程等结构应用。制备此类结构的唯一纺织制造工艺是3D编织。该项目的重点是将3D编织用于加工极脆的陶瓷纤维以及将陶瓷基体改性为更低的收缩率。该研究项目将证明三维增强CMC结构的制造是可能的，并且机械性能是上级的。特别令人感兴趣的是z轴上的钢筋与剪切强度之间的相关性。总之，这项工作提供了重要的概念和结论，在光纤加工和制造的OFC。