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

由FlightPath 2050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所塑造的航空推进领域的快速发展意味着劳斯莱斯现在面临的重大挑战是飞行的电气化。小型化涡轮驱动发电系统将被要求为稳态电力飞行提供动力，使飞机能够大大超过今天的燃油经济性。航空发动机效率的主要决定因素是涡轮机的工作温度，其中来自燃烧室的热气中的大部分能量用于驱动发动机的前端，压气机用于维持燃烧，风扇用于产生和放大推力。涡轮机最热部分的部件由镍高温合金制成，采用数十年来开发和改进的铸造技术生产单晶。每个单晶铸件由超过10^24个（1后面有24个零）原子组成，这些原子以共同的方式排列在一个单位单元中-原子尺度的“积木”。这不仅赋予了它们惊人的强度，还赋予了它们在载荷下随相对于晶胞方向而变化的机械性能。制造SX高温合金铸件的熔炉技术非常先进，旨在避免凝固前沿缓慢移动通过铸件的破裂，从而允许原子添加到先前的固体中。然而，有时会形成二次取向不良的晶粒，其中原子排列成不同取向的晶胞;在边界中有缺失的原子和键，以及不同的结构-“双晶体”。含有双晶体的铸件的大部分不能使用，因为它们的功能被认为会导致部件寿命的过度降低。拒绝的标准有利于服务安全。双晶体的形成机制还没有完全被理解，物理冶金和工艺冶金仍然是工程和制造的基石。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越来越苛刻的条件下的使用性能。它们的安全使用要求了解其能力的极限，反过来，对机械的理解又刺激了为未来应用开发改进的材料和工艺。新的或改进的合金和技术通常通过提高商业竞争力来提供经济影响。这个繁荣合作伙伴关系的战略目标是深入研究晶体各向异性和单晶成核效应（《双城之战》）是了解在单晶铸造的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高保真模拟的成核和生长的双晶体在固体，半固体和液体制度的铸造过程。我们的目标是了解各向异性高温合金单晶的相关材料特性，以及与铸造过程中形成的双晶相关的特性。这种级别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过程中开发的模型。此外，我们将利用劳斯莱斯制造和发动机数据的大量存储，以确保我们的建模和物理实验专门针对改进

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