Structure-property relations of materials having complex microstructures generated by radiation damage and Additive Manufacturing

金属相加制造是一种新技术，它可以显著提高传统方法无法制造的机械零件的定制化生产和3D打印。依赖于复杂的精密制造结构的工程应用将从这些新能力中受益匪浅。这项拟议的研究计划旨在探索AM为核反应堆和用于识别暗物质的灵敏天体物理探测器制造的部件将如何在强度、可靠性和纯度方面与传统制造的部件进行比较。核技术和探测器技术的发展引起了加拿大政府的高度关注和大力支持。这项提案将调查AM核材料在辐射下是如何退化的。随着核反应堆的老化，堆芯结构被削弱，因为它暴露在高温和高能辐射下，由活跃的核燃料。为了测试新型AM组件在反应堆中发现的条件下的耐久性和可靠性，我们将研究在辐射轰击下金属合金中的缺陷是如何积累的，以及随后它们的强度是如何变化的。我们将通过电子显微镜检查微观缺陷的数量以确定其类型，并在Balogh博士的现代X射线实验室通过X射线散射来量化辐射过程中产生的缺陷数量。我们将特别关注动力循环对缺陷积累的影响，因为这对加拿大未来的反应堆设计非常重要。这些信息对于了解不断积累的缺陷是如何损坏机械部件以及预测它们何时需要更换、避免代价高昂的意外停机非常关键。大型、灵敏的天体物理探测器依赖于由放射性纯铜制成的独特形状的结构组件，这意味着它们已经非常低的自然放射性通过各种净化方法进一步降低。这项拟议的工作旨在找到AM工艺的最佳条件/设置，以便在获得机械可靠部件的同时保持铜的放射性纯度。从事这项研究的4名博士、2名硕士和本科生将沉浸在由亚瑟·B·麦克唐纳加拿大天体粒子物理研究所培育的独特的跨学科和多样化的环境中。他们将接受材料表征技术、AM和核技术方面的培训，这些都是学术界和工业界都感兴趣的领域。这项研究将有助于天体粒子物理学家正在努力寻找一种直接探测暗物质的方法。它还将帮助加拿大核工业--每年为加拿大经济贡献超过60亿美元，并维持4万多个就业机会--掌握新知识，并在未来招聘高素质人员。

Additive Manufacturing (AM) of metals is a novel technology which can significantly advance the production of custom-made components and 3D printing of mechanical parts not manufacturable by conventional means. Engineering applications relying on complex precision-made structures, would significantly benefit from these novel capabilities. The proposed research program aims to explore how components made by AM for nuclear reactors and for sensitive astrophysics detectors designed to identify dark matter will compare in strength, reliability and purity to conventionally manufactured parts. The development of both nuclear and detector technology are of high interest and strongly supported by the Government of Canada. This proposal will investigate how AM nuclear materials deteriorate under irradiation. As nuclear reactors age, the structure of the core is weakened because it is exposed to high temperature and energetic radiation by the active nuclear fuel. To test the durability and reliability of novel AM components under conditions found in a reactor, we will investigate how defects accumulate in metal alloys when bombarded with radiation, and subsequently how their strength changes. We will inspect the population of the microscopic defects by electron microscopy to determine their type, and by X-ray scattering in Dr. Balogh's modern X-ray laboratory to quantify the amount of defects produced during irradiation. We will give special attention to the effect of power-cycling on the accumulation of defects as it is of high-interest for future Canadian reactor designs. This information is key for understanding how the steadily accumulating defects deteriorate the mechanical components and for anticipating when they need replacement avoiding expensive unscheduled shutdowns. Large-scale, sensitive astrophysics detectors rely on uniquely-shaped structural components made from radiopure copper, meaning that their already very low natural radioactivity is reduced further by various purification methods. The proposed work aims to find the optimal conditions/settings for the AM process in order to obtain mechanically reliable parts while also preserving the radio-purity of copper. A blend of 4 PhD, 2 MSc and undergraduate students working on the proposed research will be immersed in a uniquely interdisciplinary and diverse environment fostered by the Arthur B. McDonald Canadian Astroparticle Physics Research Institute. They will be trained in materials characterization techniques, AM and nuclear technology, areas of interest to both academia and industry. This research will contribute to the on-going search effort of astroparticle physicists for a method to directly detect dark matter. It will also help the Canadian nuclear industry-which contributes over $6 billion/year to the Canadian economy and sustains more than 40,000 jobs-with new knowledge and future recruitment of highly qualified personnel.