Degradation of the thermal and mechanical properties SiCf/SiCm composite with irradiation

辐照下 SiCf/SiCm 复合材料的热性能和机械性能下降

• 批准号: 2764488
• 金额: --
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2764488
• 关键词: Degradation; thermal; mechanical; properties; SiCf

An exciting opportunity to contribute to the application of SiC-based ceramic matrix composites in nuclear fission and its translation to fusion. For this project the MSE-F group (UKAEA) will supply four different grades of SiCf/SiCm available from international industrial partners. The PhD student on this project will be based at the University of Bristol and is anticipated to spend a significant amount of time at UKAEA to conduct relevant experiments, such as micromechanical testing and Focus Ion Beam tomography characterisation.Materials able to operate at extreme temperatures, resisting high-flux neutron irradiation damage while remaining structurally stable are needed for components in nuclear fission, e.g., as accident tolerant fuel cladding, as well as nuclear fusion including STEP (Spherical Tokamak for Energy Production) and DEMO. In particular, it has been recognised that silicon-carbide (SiC) fibre reinforced SiC matrix composites (SiCf/SiCm), which has low neutron absorption, high thermal conductivity, high fracture toughness, excellent chemical/mechanical stability at elevated temperatures (e.g., ~1000C), are able to provide the highest thermodynamic efficiency nuclear structural components.During this project, the PhD student will first conduct a review regarding the available irradiation data in open literature for this class of materials, and design subsequent irradiation experiments using energetic ions, protons or neutrons. The irradiated samples will be examined in terms of their micro-mechanical properties, depends on the thickness of the surface irradiated layer, conventional nano-indentation or more sophisticated micro-cantilever bending/pillar compression tests will be conducted. The thermal conductivity degradation of the SiC fibre and matrix, which is a function of the irradiation damage, will be measured using high-resolution TTR (transient thermoreflectance) method which is unique in the UK where Bristol has about 20 years' experience.In addition, a unique in situ high temperature X-ray micro-tomography technique will be used to investigate the deformation and fracture of unirradiated SiCf/SiCm. This will study only the effect of service temperature on the material's mechanical behaviour in terms of strength/failure strain, crack initiation and propagation when loaded under conditions similar to service.

这是一个激动人心的机会，可以为碳化硅基陶瓷基复合材料在核裂变及其转化为聚变方面的应用做出贡献。对于该项目，MSE-F 集团（UKAEA）将从国际工业合作伙伴处提供四种不同等级的 SiCf/SiCm。该项目的博士生将在布里斯托大学工作，预计将在 UKAEA 花费大量时间进行相关实验，例如微机械测试和聚焦离子束断层扫描表征。能够在极端温度下工作的材料，核裂变组件需要抵抗高通量中子辐照损伤，同时保持结构稳定，例如耐事故燃料包壳，以及包括STEP（球形核聚变）在内的核聚变组件。用于能源生产的托卡马克）和演示。特别是，碳化硅（SiC）纤维增强SiC基复合材料（SiCf/SiCm）已被认为具有低中子吸收、高导热性、高断裂韧性、高温下优异的化学/机械稳定性（例如， ~1000C），能够提供最高热力学效率的核结构部件。在这个项目中，博士生将首先对此类材料的公开文献中可用的辐照数据进行审查，并设计后续使用高能离子、质子或中子的辐照实验。辐照样品将根据其微观机械性能进行检查，具体取决于表面辐照层的厚度，将进行传统的纳米压痕或更复杂的微悬臂梁弯曲/柱压缩测试。 SiC 纤维和基体的热导率下降是辐照损伤的函数，将使用高分辨率 TTR（瞬态热反射）方法进行测量，该方法在英国是独一无二的，布里斯托尔在英国拥有约 20 年的经验。此外独特的原位高温X射线显微断层扫描技术将用于研究未辐照SiCf/SiCm的变形和断裂。这将仅研究在与使用类似的条件下加载时，使用温度对材料机械行为的影响，包括强度/失效应变、裂纹萌生和扩展。