The micromechanics of ductile to brittle fracture in polycrystals

多晶韧脆断裂的微观力学

• 批准号: RGPIN-2022-02955
• 负责人: Abdolvand, Hamidreza
• 金额: $ 2.4万
• 依托单位: University of Western Ontario
• 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=759837
• 关键词: micromechanics; ductile; brittle; fracture; polycrystals

Climate change is one of the most important challenges of our time that should be addressed. It is caused by the increase in the concentration of greenhouse gases. To reduce the emissions, several recommendations are made, e.g., the use of electric vehicles or the integration of combined renewable and non-emitting power production to the electricity grid. In Ontario, this has translated to $25B investment on the refurbishment of the CANada Deuterium Uranium (CANDU) nuclear reactors which has been taking place since 2013 and is scheduled to finish in 2033. As a source of reliable energy that stabilizes the electricity grid, CANDU reactors have been producing more than 50% of zero-emission electricity in Ontario, and 15% nationwide. To further maintain the production of clean nuclear energy, the National Resources Canada has recently prepared a roadmap for developing and deploying Small Modular Reactors (SMRs). To use such advanced technologies, however, there are several barriers that should be overcome. This includes improving the public acceptance of nuclear energy, and reducing the cost of running CANDUs or building SMRs by improving the lifespan of the materials used in the core of the reactors. Improving the lifespan of these materials requires the development of advanced toolboxes that help understand the underlying mechanisms that control their degradation. This program focuses on the development and validation of advanced multiphysics multiscale numerical models to study the degradation mechanisms of the metal alloys used in the core of nuclear reactors. The models will be used to study how short cracks nucleate at the nano and microscales and how they propagate and eventually affect the lifespan of engineering components. Most importantly, for the first time, the effects of neutron irradiation from fission reactions on the embrittlement and fracture of metal alloys will be studied. Attentions will be given to the materials used in the core of CANDU reactors and the potential candidates for SMRs. In addition, advanced diffraction-based and image-based experimental techniques will be developed or used to validate the numerical models. The results will be coupled with machine learning algorithms to enhance the efficiency of the developed methods. The outcomes of this program will help understand the underlying mechanisms that control both ductile and brittle failure of metal alloys. This will reduce the cost of excessive experimentation of reactor materials and will provide more accurate methods for estimating components lifespans. It will help relax the over-conservative safety standards used in nuclear industry which will subsequently help reduce the cost of running the reactors. In addition, this program is designed to improve the public acceptance of nuclear energy by improving equity, diversity, and inclusion in this field through training a diverse group of highly qualified personnel.

气候变化是应解决的时代最重要的挑战之一。这是由于温室气体浓度的增加引起的。为了减少排放，提出了几种建议，例如使用电动汽车或将可再生和非发射功率产生的组合到电网上。在安大略省，这已经转化为25B美元的投资，用于翻新加拿大铀铀（Candu）核反应堆，该反应堆自2013年以来一直在发生，并计划在2033年完成。作为可靠的能源，作为稳定电网电网的可靠能量的来源，Candu反应堆已经销量超过50％的零压力电动机和15％的国家，以及15％的intario，且15％的nationwide＆15％natirio，以及15％的intario，以及15％的intario＆15％沃尔特（15％）。为了进一步维持清洁核能的生产，加拿大国家资源最近为开发和部署小型模块化反应堆（SMR）准备了路线图。但是，要使用这种先进的技术，应该克服多个障碍。这包括改善公众对核能的接受，并通过改善反应堆核心中使用的材料的寿命来降低运行糖果或建造SMR的成本。改善这些材料的寿命需要开发先进的工具箱，以帮助了解控制其降解的潜在机制。该计划着重于先进的多物理多尺度数值模型的开发和验证，以研究核反应堆核心中使用的金属合金的降解机制。这些模型将用于研究纳米和显微镜的短裂纹如何成核以及它们如何传播并最终影响工程组件的寿命。最重要的是，将首次研究裂变反应中的中子照射对金属合金的含量和断裂的影响。将注意Candu反应堆核心中使用的材料以及SMR的潜在候选物。另外，将开发或用于验证数值模型的基于高级衍射和基于图像的实验技术。结果将与机器学习算法相结合，以提高开发方法的效率。该程序的结果将有助于了解控制金属合金的延性和脆性衰竭的潜在机制。这将降低反应堆材料过度实验的成本，并将提供更准确的方法来估计组件寿命。它将有助于放松核工业中使用的过度保守安全标准，随后将有助于降低运行反应堆的成本。此外，该计划旨在通过培训一组高素质的人员来改善该领域的公平，多样性和包容性，从而改善公众对核能的接受。