Development of hybrid advanced manufacturing FAST-forge route for next generation aerospace components

近年来，谢菲尔德大学的研究人员开发了一种混合固态加工路线，通过两个步骤将钛合金粉末转化为完全致密的零件。第一步利用快速烧结工艺--场辅助烧结技术(FAST)来固结一系列钛粉和颗粒。FAST与传统的烧结方法不同，因为电流流过粉末以实现焦耳加热效果，而不是使用外部热源。该团队展示了PREP、HDH、GA等粉末的固结，以及一系列钛合金化学物质的机械加工碎屑。该工艺生产的密度与热等静压(HIP)相当，但FAST的优势包括固化时间长达1小时(而HIPing为4小时)，以及无需灌装的成型预制件。第二步：谢菲尔德的研究人员利用FAST的好处，将其作为后续一步锻造阶段的中间工艺，以提供增强的机械性能。FAST-FORGE现正被用于中小型钛合金起落架部件。FAST作为一种粉末固态扩散连接技术的好处最近已经实现(称为FAST-DB)。用这种固态技术成功地连接了劳斯莱斯钛合金和镍高温合金粉末。潜在的FAST-DB可以被开发成一种制造路线，可以为部件提供具有多合金区域的部件，例如，增强关键子部件区域的蠕变和疲劳性能，最终提高航空部件的寿命。本项目的目的是开发和进一步了解航空合金粉末的FAST-DB和快速锻造的特点。其目的是使用ThermoCalc、Deform和COMSOL软件为工业规模的快速衍生组件生成预测模型。一个关键的演示组件的例子可能是压缩机叶片，其中翼型和燕尾翼可能使用不同的钛合金。该项目与亨利·罗伊斯研究所专用的大型设备以及EPSRC未来制造中心MAPP(使用先进粉末工艺制造)的目标保持一致。项目结束时的目标是将知识转移到高价值弹射器中心，用于大规模工业开发。通过EngD，您将在钛和/或镍高温合金冶金、工艺建模、快速、形变加工、机械测试、一系列表征技术(电子显微镜、X射线衍射仪)、有限元建模(DEFORM)、基于物理的建模(COMSOL)和热力学建模(ThermoCalc)方面获得宝贵的职业生涯定义经验。你将被要求每周向劳斯莱斯展示结果，并与他们的材料和工艺建模团队接触

Over recent years, researchers at The University of Sheffield have developed a hybrid solid-state processing route that converts titanium alloy powder into fully dense parts in two steps. Step 1 exploits the rapid sintering process - field-assisted sintering technology (FAST) to consolidate a range of titanium powder and particulates. FAST is different from conventional sintering methods as a current flows through the powder to achieve a Joule heating effect instead of using an external heat source. The team have demonstrated the consolidation of powders such as PREP, HDH, GA and machined swarf of a range of titanium alloy chemistries. The process produces densities comparable to hot isostatic pressing (HIP), however the advantages of FAST include consolidation times of up to 1 hour (as opposed to 4 hours in HIPing) and shaped preforms without the need for canning. Step 2; researchers at Sheffield have exploited the benefits of FAST to be an intermediate process for a subsequent one step forging stage to provide enhanced mechanical properties. FAST-forge is now being exploited for small to medium sized titanium alloy landing gear components.The benefits of FAST as a solid state diffusion bonding technique for powder have recently been realised (known as FAST-DB). Rolls-Royce titanium alloy and nickel superalloy powders have been successfully bonded using such a solid state technique. Potentially FAST-DB can be developed into a manufacturing route that can provide components with multi-alloy regions, for example to enhance creep and fatigue resistance in key subcomponent regions, ultimately increasing the life of aerospace components. The aim of this EngD is to exploit and further understand the characteristics of the FAST-DB and FAST-forge for aerospace alloy powders. The aim is to use ThermoCalc, DEFORM and COMSOL software to produce predictive models for industrial scale FAST derived components. An example of a key demonstrator component could be a compressor blade where different titanium alloys may be used for the aerofoil and dovetail. The project aligns with the large scale equipment earmarked for the Henry Royce Institute and objectives of the EPSRC Future Manufacturing Hub MAPP (Manufacture using Advanced Powder Processes). The objectives at the end of the project will be to transfer the knowledge to the High Value Catapult Centres for large scale exploitation into industry.Through the EngD you will be gain valuable and career defining experience in titanium and/or nickel superalloy metallurgy, process modelling, FAST, thermomechanical processing, mechanical testing, a range of characterisation techniques (electron microscopy, XRD), finite element modelling (DEFORM), physics-based modelling (COMSOL) and thermodynamic modelling (ThermoCalc). You will be expected to present results to Rolls-Royce on a weekly basis and engage with their materials and process modelling teams