Modelling radiation resistant low activation High Entropy Alloys

联合王国政府的政策是，核能在提供一个安全、低碳、废物产生最少的能源未来方面发挥重要作用;例如，在一个实施例中，今年夏天，政府发布的《核部门协议》文件将优先考虑“以创新为导向的增长的长期愿景，该愿景将连续降低发电成本，并将纳税人的退役成本降低20%”2018年，英国约20%的电力来自核反应堆，对电能的需求可能只会增加，例如，通过交通的电气化。在短期内，小型模块化反应堆（SMR）和第三代技术可以用来满足需求。开发用于下一代核反应堆的抗辐射合金将有助于维持和扩大英国建造先进发电厂的能力，并能够提供可靠的低碳能源。随着材料科学被强调为2016年EPSRC裂变与聚变独立审查的关键挑战，该项目将致力于利用先进的计算机建模和模拟来解决功能材料的挑战。因此，在该项目中，原子模型高熵合金（HEAs）将被开发和模型用于研究特定的低活化的机械和热性能（即它们在很长一段时间内不会变得具有高放射性）HEA是一种新型合金，其中没有单一的金属元素占主导地位，四种或更多种元素以接近相等的原子比使用。HEA目前是重要的国际研究努力的主题，这是由于其与常规合金相比所报道的上级机械性能，例如优异的硬度和高温强度和稳定性。因此，他们有很好的潜力，为核应用提供他们不成为活跃的辐射。各种理论模型的基础上从头算技术将实施调查的机械和热性能，这些将与实验进行比较。然而，由于计算的限制，可以使用从头计算方法研究的系统尺寸必然很小，因此该项目的第二个目的是通过将从头计算结果与经典的潜在形式主义联系起来，通过使用多尺度建模来研究更大的系统。这将使合金在辐照下的行为也被调查，并与其他更传统的材料进行比较。该项目将集中在减少激活HEAs的调查，特别是那些包括TiVZrTa和VWMoCr和TiVCrMnFe，这将在相关的实验计划中加以考虑，但将要开发和使用的技术将普遍应用于其他复杂合金，因此，在核领域之外的潜在广泛应用。

The UK Government policy is that nuclear energy has an important role to play in providing an energy future that is safe and low carbon with minimal waste production; for example, the Government's "Nuclear Sector Deal" paper published this summer has as a priority "a long-term vision of innovation-led growth that delivers successively lower generation costs and a 20% reduction in decommissioning costs to the taxpayer".In 2018, the UK derived ~20% of its electrical power from nuclear reactors and it is likely that demand for electrical energy will only increase, e.g., through the electrification of transport. In the short term, small-modular reactors (SMR) and Gen-III technologies may be utilised to meet demand. The development of radiation-resistant alloys for use in next-generation nuclear reactors will help sustain and expand the UK's capacity to build advanced power plants, with the ability to deliver reliable low-carbon energy. With Materials science highlighted as the key challenge in the 2016 EPSRC Independent Review of Fission and Fusion, this project will aim at addressing the functional materials challenge using advanced computer modelling and simulation.Therefore in this project, atomistic models High Entropy Alloys (HEAs) will be developed and the models used to investigate the mechanical and thermal properties of specific low activation (i.e. they do not become highly radioactive for long periods) HEAs. HEAs are novel alloys where no single metallic element dominates and four or more elements are used in near equal atomic ratios. HEAs are currently the subject of a significant international research effort due to their reported superior mechanical properties compared to conventional alloys, such as excellent hardness and high temperature strength and stability. They have therefore excellent potential for nuclear applications provided they do not become active under irradiation.Various theoretical models based on ab initio techniques will be implemented to investigate mechanical and thermal properties and these will be compared to experiment. However the system sizes that can be studied using ab initio methods are necessarily small due to computing limitations and so a second aim of the project is to study larger systems through the use of multi scale modelling by linking the ab initio results with a classical potential formalism. This will allow the alloy behaviour under irradiation also to be investigated and the results compared with other more conventional materials.The project will concentrate on the investigation of reduced activation HEAs specifically those comprising of TiVZrTa and VWMoCr and TiVCrMnFe, which will be considered in a related experimental programme but the techniques that will be developed and used will have a general application to other complex alloys and therefore potentially wide use outside the nuclear area.