Advanced Research into Crystallographic Anisotropy & Nucleation Effects in single crystals (ARCANE)

“飞行路径2050”的目标、商业压力、可能的立法，以及至关重要的不断变化的公众需求，塑造了航空推进领域快速发展的格局，这意味着罗尔斯·罗伊斯现在面临的最大挑战是飞行电气化。小型化的涡轮驱动发电系统将需要为稳态电动飞行提供动力，使飞机的燃油经济性大大超过今天的水平。这需要扩展和增强现有的引擎设计和其中的组件，或者全新的设计。航空发动机效率的主要决定因素是涡轮的工作温度，其中来自燃烧室的热气体中的大部分能量用于驱动发动机的前端，压气机维持燃烧，风扇产生并扩大推力。涡轮机最热部分的部件是由镍高温合金制成的，使用了几十年来发展和改进的铸造技术来生产单晶。单晶（SX）铸件由超过10^24（1后面跟着24个零）个原子组成，排列成一个单元——原子尺度的“积木”。这使它们具有惊人的强度，而且在载荷下的机械性能也随着相对于单元格的方向而变化。制造SX高温合金铸件的熔炉技术是非常先进的，其设计旨在避免在铸件中缓慢移动的凝固前沿被破坏，从而使原子能够添加到先前的固体中。然而，有时会形成二次取向错误的晶粒，其中原子排列在不同取向的单晶上；在边界上有缺失的原子和键，以及不同的结构——“双晶体”。很大一部分含有双晶的铸件不能使用，因为它们的功能被认为会导致部件寿命的过度减少。它们的拒绝标准有利于使用中的安全性。双晶形成的机制还没有被很好地理解。物理和工艺冶金仍然是工程和制造业的基石。只有通过充分详细的机械理解和模型来预测材料的行为，才能有信心地预测它们在更苛刻条件下的使用性能。它们的安全使用要求理解能力的限制，反过来，对机械的理解刺激了未来应用的改进材料和工艺的发展。新的或改进的合金和技术通常通过提高商业竞争力提供经济影响。“单晶晶体各向异性与成核效应高级研究”（ARCANE）的战略目标是了解单晶铸造各向异性世界中缺陷的成核。我们的目标是实现世界上第一个在固态、半固态和液态铸造过程中双晶形核和生长的高保真模拟。我们的目的是了解各向异性高温合金单晶的相关材料性能，以及铸造过程中形成的双晶的相关材料性能。这一水平的模拟将需要在各个层面上取得突破，包括物理模型、数值求解器和新算法。我们将使用最先进的铸造实验和材料评估来验证我们在研究期间开发的模型。此外，我们将利用大量的劳斯莱斯制造和发动机数据来确保我们的建模和物理实验是专门针对改进的

The rapidly evolving landscape for aviation propulsion - shaped by FlightPath 2050 objectives, commercial pressures, likely legislation, and crucially, a changing public demand - means that Rolls-Royce's grand challenge is now the electrification of flight. Miniaturised turbine-driven electrical generating systems will be required to power steady-state electric flight, enabling aircraft to vastly exceed the fuel economies of today. This necessitates both scaling and enhancing existing engine designs and the components within them or radically new designs.The principal determinant of aero engine efficiency is the temperature of operation of the turbine, in which much of the energy in the hot gas from the combustor is used to drive the front end of the engine, both the compressor to sustain combustion and the fan to create and amplify thrust. The components of the hottest part of the turbine are manufactured from nickel superalloys using casting technology developed and refined over decades to produce single crystals. Single crystal (SX) castings are each comprised of more than 10^24 (1 with 24 following zeros) atoms arranged in common alignment to a unit cell - the atomic scale 'building block'. This imbues them with astonishing strengths but also mechanical properties under load that vary with direction relative to the unit cell.Furnace technologies to make SX superalloy castings are highly advanced, being designed to avoid breakdown of the solidification front that moves slowly through the casting allowing atoms to be added to the prior solid. However, sometimes a secondary misoriented grain is formed, within which the atoms are aligned to a unit cell of different orientation; in the boundary there are missing atoms and bonds, as well as different structures - the "bicrystal". A large proportion of castings that contain bicrystals cannot be used as their function is considered to result in excessive decrease in component life. Criteria for their rejection favour safety in service. The mechanisms of bicrystal formation are not at all well understood.Physical and process metallurgy remains a cornerstone of engineering and manufacturing. Only by having a sufficiently detailed mechanistic understanding and models to predict how materials behave can their performance in service under ever more demanding conditions be predicted with confidence. Their safe use demands that limits of capability are understood and in turn mechanistic understanding stimulates the development of improved materials and processes for future applications. New or improved alloys and technologies often provide economic impact through increased commercial competitiveness.The strategic goal of this Prosperity Partnership for Advanced Research into Crystallographic Anisotropy & Nucleation Effects in single crystals (ARCANE) is to understand the nucleation of defects in the anisotropic world of single crystal casting. Our aim is to achieve the world's first high fidelity simulation of the nucleation and growth of bicrystals in the solid, semi solid and liquid regimes of the casting process. We aim to understand the associated materials properties of the anisotropic superalloy single crystals, as well as the properties associated with bicrystals formed during casting. This level of simulation will require breakthroughs at all levels, including physical models, numerical solvers and novel algorithms. We will use state of the art casting experimentation and materials evaluation to verify the models that we develop during the research. Furthermore, we will use the vast store of Rolls-Royce manufacturing and in engine data to ensure that our modelling and physical experimentation is targeted specifically for improvements