Novel braze coating materials & processes for sustainable aeroengine applications

新型钎焊涂层材料

• 批准号: 2604568
• 金额: --
• 依托单位: Swansea University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2604568
• 关键词: Novel; braze; coating; materials; processes

BackgroundReaction Engines (https://www.reactionengines.co.uk) are developing expertise in propulsion systems for alternative fuels, such as ammonia, as part of the shift in technologies targeting "sustainable flight". A core aspect of the goal of high speed, energy efficient flight are the heat exchanger designs used by Reaction Engines to cool high speed fluids, and to recover and re-use the heat energy extracted. One of the key design configurations is tubular heat exchangers, which provide light-weight, compact, efficient performance. The primary manufacturing technique enabling the novel designs to be assembled is Vacuum Brazing. Reaction Engines have considerable experience in design, manufacturing, and testing of tubular heat exchangers in both nickel-chromium super alloys, and stainless-steel alloys, brazed in-house using a large state-of-the-art bespoke vacuum furnace. Multiple rows of thin-walled tubing are joined to manifolds in tightly packed complex arrays, in shapes that can be packaged in compact modular designs.Reaction Engines are developing the vacuum brazed heat exchanger assemblies further, as designs gain traction in the aerospace sectors, and other sectors demanding high levels of performance, in applications requiring certification. As production volumes increase, the level of quality assurance and repeatability will have to increase also. Various aspects of the Vacuum Brazing process must be optimised. The selection of the braze consumable alloy, which flows into the joint gaps, is one of these aspects. Well established, off-the-shelf products are currently used. Improvements are sought via the investigation of novel compositions and formats. As well as the base composition of the braze consumable alloy, the format of it is also important (paste, wire, foil, tape options exist). These different formats offer different advantages in terms of how the braze consumable is locally deposited on to the metal substrates. Both the melting behaviour of the alloy consumable at the brazing temperature, and the ease of application of the alloy consumable at the required locations are key factors to be optimised for the Reaction Engine Tubular Heat Exchanger designs, to increase efficiency of manufacturing in the Assembly and Brazing production areas. Application of uniform layers of braze consumable on to the surfaces via coating technologies are one of the methods whereby process efficiencies will be assessed.Project AimsThe work will start with the comprehensive undertaking of mapping Reaction Engines' existing assembly and vacuum brazing routes for heat exchanger parts. A baseline material and manufacturing component will be identified for both steel and nickel alloy parts, representative of current tubular heat exchanger designs. An assessment of existing commercial brazing alloys will be done to understand the current limits for repeatability, and performance. Methods for application of the brazing consumable to the component surfaces, at the required locations, will be assessed - laser cladding, thermal spray, cold spray, physical vapour deposition, or hybrid surface additive manufacturing routes are coating methods of interest. The manually intensive placement methods currently in use will be replaced. Materials characterisation will be undertaken to identify optimal process parameters and material properties, including mechanical testing, metallography and thermophysical property measurement. In a final stage novel coating alloys (e.g., high entropy alloys) will be formulated, manufactured, and tested for comparison to the existing commercial systems.

背景反射引擎（https://www.reactionengines.co.uk）正在开发针对替代燃料（例如氨（例如氨）的推进系统的专业知识，作为针对“可持续飞行”的技术转变的一部分。高速效率飞行目标的一个核心方面是反应发动机用来冷却高速流体的热交换器设计，并恢复并重新使用提取的热能。关键设计配置之一是管状热交换器，可提供轻巧，紧凑，高效的性能。使新设计组装的主要制造技术是真空悬挂的。反应发动机在镍铬超级合金中的管状热交换器的设计，制造和测试方面都有丰富的经验，以及使用大型的最先进的定制真空炉内部的不锈钢合金。连接了多排薄壁管以在紧密堆积的复杂阵列中进行歧管，形状可以包装在紧凑的模块化设计中。反射引擎正在开发真空悬挂的热交换器组件，因为设计进一步增强了航空航天领域的牵引力，要求高水平的绩效，以及其他要求高水平的绩效认证。随着生产量的增加，质量保证和可重复性的水平也必须提高。真空悬挂过程的各个方面必须优化。这些方面的选择是流入关节间隙的铜管消耗合金。目前使用了良好的现成产品。通过研究新颖的组成和格式来寻求改进。除了铜管消耗合金的基本组成之外，它的格式也很重要（粘贴，电线，箔，胶带选项存在）。这些不同的格式在局部沉积在金属基板上的方式方面具有不同的优势。在瓦斯温度下消耗的合金的熔融行为以及在所需位置消耗的合金的易用性都是应针对反应发动机管状热交换器设计优化的关键因素，以提高组装和武装生产区域的制造效率。通过涂层技术在表面上消耗的均匀层涂层是评估过程效率的方法之一。代表当前管状热交换器设计的代表钢和镍合金零件的基线材料和制造成分。将对现有的商业铜合金进行评估，以了解可重复性和性能的当前限制。将评估在所需位置使用悬挂在组件表面上的腌制的方法 - 激光覆层，热喷雾，冷喷雾，物理蒸气沉积或混合表面添加剂制造途径是感兴趣的涂料方法。当前正在使用的手动密集放置方法将被替换。将进行材料表征，以确定最佳的过程参数和材料特性，包括机械测试，金理图和热物理性能测量。在最后一阶段的小说涂层（例如，高熵合金）将被制定，制造和测试，以与现有的商业系统进行比较。