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，通过两步将钛合金粉末转化为完全致密的零件。第1步利用快速烧结工艺-场辅助烧结技术（FAST）来巩固一系列钛粉末和颗粒。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应，而不是使用外部热源。该团队已经展示了粉末的固结，如PREP，HDH，GA和一系列钛合金化学品的机加工切屑。该工艺生产的密度与热等静压（HIP）相当，但FAST的优点包括固结时间长达1小时（而HIP中为4小时），并且无需罐装即可成型预制件。步骤2;谢菲尔德的研究人员已经利用FAST的优点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锻造目前正用于中小型钛合金起落架部件。FAST作为粉末固态扩散连接技术的优点最近已经实现（称为FAST-DB）。罗尔斯-罗伊斯公司的钛合金和镍高温合金粉末已成功地使用这种固态技术连接。FAST-DB可能会发展成为一种制造路线，可以为部件提供多合金区域，例如增强关键子部件区域的抗蠕变性和抗疲劳性，最终增加航空航天部件的寿命。本工程的目的是开发和进一步了解航空航天合金粉末的快速DB和快速锻造的特点。目的是使用ThermoCalc、DEFORM和COMSOL软件为工业规模的FAST衍生组件生成预测模型。一个关键演示部件的例子可能是压气机叶片，其中不同的钛合金可用于翼型和燕尾榫。该项目符合亨利罗伊斯研究所的大型设备和EPSRC未来制造中心MAPP（使用先进粉末工艺制造）的目标。项目结束时的目标是将知识转移到高价值弹射器中心，以进行大规模的工业开发。通过EngD，您将获得钛和/或镍高温合金冶金，工艺建模，FAST，热机械加工，机械测试，一系列表征技术的宝贵和职业定义经验。（电子显微镜，XRD）、有限元建模（DEFORM）、基于物理的建模（COMSOL）和热力学建模（ThermoCalc）。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合作

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