Effect of local microstructure on cracking of materials for next generation reactors

局部微观结构对下一代反应堆材料开裂的影响

• 批准号: RGPIN-2020-03904
• 负责人: Daymond, Mark
• 金额: $ 5.54万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=759845
• 关键词: Effect; local; microstructure; cracking; materials

The global drive for low-carbon energy sources, combined with a growing worldwide energy consumption, is a challenge to which nuclear energy, in combination with renewables such as wind and solar, provides a realistic, sustainable solution. Canada aims to position itself at the forefront of advanced nuclear reactor designs, with substantial investment in the development of small nuclear modular reactors (SMRs). However, SMRs are still a decade from implementation, and a range of urgent questions must first be answered. Many of the limitations to SMR delivery arise from materials issues: how they will respond, age and fail under the conditions they will experience. This proposal will address key basic research questions into material performance, which will be required to enable safe SMR operation. Specifically, it will investigate the damage processes associated with irradiation in SMR-proposed materials, and the subsequent effect on fracture and especially fatigue of SMR-relevant metals. Real materials are made up of grains or crystallites - each individual crystallite is typically highly anisotropic in its response to stress. In many practical applications we cannot ignore this local heterogeneity and must understand how irreversible microstructural changes occur and propagate at this local scale. Diffraction techniques are able to reveal many of the microstructural changes which will have an influence, including inter-granular strains induced by elastic and plastic crystallographic anisotropy, intra-granular strains generated by crystallographic defects (dislocations), as well as deformation-induced phase transformations or crystallographic reorientation. The aim of this proposal is to investigate the extent to which monitoring these effects can provide insights into understanding the mechanisms of fatigue and the processes of initial crack propagation. In addition, we will investigate the way that irradiation influences microstructural damage accumulation. While temperature and stress provide two key variables that influence material properties, they are not the only ones. Materials behave differently in an energetic radiation environment (e.g., in a nuclear reactor or in space) than in conventional applications due to the flux of high energy particles which introduce point defects and dislocations, and alter the microchemistry of the material. This proposal will train HQP directly in advanced techniques (both experimental and modeling) and in a research area which is of current and ongoing interest to a wide range of industry, not just nuclear power. Building on existing successes, it will strive to deliver a diverse group of HQP with skills and knowledge that will be valuable to Canadian industry.

全球对低碳能源的追求，加上全球能源消费的不断增长，是核能与风能和太阳能等可再生能源相结合所面临的挑战，是一种现实的、可持续的解决方案。加拿大的目标是将自己定位在先进核反应堆设计的前沿，在小型核模块反应堆(SMR)的开发上投入大量资金。然而，SMR距离实施还有十年的时间，必须首先回答一系列紧迫的问题。SMR交付的许多限制来自材料问题：他们将如何应对，在他们将经历的条件下老化和失败。这项提案将解决材料性能方面的关键基础研究问题，这将是实现SMR安全运行所必需的。具体地说，它将调查与SMR建议的材料中的辐射相关的损伤过程，以及随后对SMR相关金属的断裂和特别是疲劳的影响。真正的材料是由颗粒或微晶组成的--每个单独的微晶对应力的反应通常是高度各向异性的。在许多实际应用中，我们不能忽视这种局部异质性，必须了解在这种局部尺度上不可逆转的微结构变化是如何发生和传播的。衍射技术能够揭示许多会产生影响的微观结构变化，包括由弹性和塑性结晶学各向异性引起的晶间应变，由晶体缺陷(位错)产生的晶内应变，以及变形诱导的相变或晶体重新取向。这一建议的目的是调查监测这些影响在多大程度上能够为理解疲劳机制和初始裂纹扩展过程提供洞察力。此外，我们还将研究辐射对微结构损伤累积的影响。虽然温度和应力提供了影响材料特性的两个关键变量，但它们并不是唯一的变量。材料在高能辐射环境中(例如，在核反应堆或太空中)的行为与在常规应用中不同，这是因为高能粒子的流动引入了点缺陷和位错，并改变了材料的微观化学。这项提议将直接在高级技术(包括实验和建模)和研究领域对HQP进行培训，该领域目前和持续对广泛的行业感兴趣，而不仅仅是核电。在现有成功的基础上，它将努力提供一批多样化的HQP，拥有对加拿大工业有价值的技能和知识。