Development of the Conform Process to Recycle Titanium Alloy Swarf into Wire for Sustainable Additive Manufacturing Feedstock

与金属粉末相比，线材原料在添加剂制造过程中易于处理方面具有显著优势。此外，粉末的形态和大小规格意味着大量的粉末可能会超出要求。在送丝添加剂制造(AM)过程中，材料的使用率为100%。这使得连续挤压或符合等固态工艺在未来变得更加重要。这种严重的塑性变形过程可以将Sur+粉末、颗粒或废品，如加工切屑，转化为杆/线形式。然后将其进一步冷拔成直径5 mm的线材，用于直接能量沉积(DED)工艺。Conform自20世纪70年代以来一直用于铜和铝棒材原料。然而，近年来在谢菲尔德大学和BWE有限公司，已经证明Conform可以将Cp-Ti粉末和Ti-6Al-4V碎屑转化为具有细小等轴晶组织的完全固结的线材。下图显示了用于从粉末生产Cp-Ti线材的Conform工艺示意图。在该EngD项目中，一个关键目标将是(1)设计、制造(使用现场辅助烧结技术)和测试利用航空镍高温合金废料的高温耐磨模具，以使钛合金碎屑能够以航空航天制造业认为负担得起的延长挤压速度连续挤压。(2)确定碎屑/颗粒特性对线材组织和性能的影响，包括下游冷拔性能。其目标将是设计针对钛屑和粉末原料进行优化的模具--这将需要有限元建模。我们的长期目标是将CONFORM工艺作为一种颠覆性的、可持续的制造技术来开发和降低风险，以回收加工废料。在攻读过程冶金、材料科学(如微结构表征、有限元建模和数据分析方法)的过程中，您将发展核心技能。您将与我们的工程主管和技术人员协作，并可以使用亨利·罗伊斯研究所的高性能制造和表征设施。您将深入了解航空航天领域的先进制造技术挑战，并与DSTL的冶金专家密切合作

Compared to metal powder, wire feedstock has significant advantages in terms of ease of handling for additive manufacturing processes. In addition, powder specifications on morphology and size mean that large volumes of powder can be surplus to requirements. In wire fed additive manufacturing (AM) pro-cesses, 100% of the material is used. This makes solid state processes such as continuous extrusion or Conform even more important in the future. Such severe plastic deformation processes can convert sur-plus powder, particulate or waste product, such as machining swarf, into a rod/wire form. This can then be further cold drawn into <5 mm diameter wire for direct energy deposition (DED) processes. Conform has been used since the 1970s for copper and aluminium rod feedstocks. However, over recent years at the University of Sheffield and BWE Ltd, it has been demonstrated that Conform can be adapted to con-vert CP-Ti powder and Ti-6Al-4V swarf into fully consolidated wire with a fine, equiaxed grain struc-ture. The figure below shows a schematic of the Conform process used for the the production of CP-Ti wire from powder. In this EngD project a key aim will be to (1) design, make (using field-assisted sintering technology) and test high temperature, wear resistant tooling from aerospace nickel superalloy waste in order to enable titanium alloy swarf to be continuous extruded at prolonged rates that are deemed affordable for the aer-ospace manufacturing industry. (2) determine the effect of swarf/particulate characteristics on wire mi-crostructure and properties, including downstream cold drawability. The aim will be to design tooling optimised for titanium swarf and powder feedstocks - which will require finite element modelling. The long term ambition is to develop and de-risk the Conform process as a disruptive, sustainable manufac-turing technology to recycle machining waste.During your EngD you will develop core skills in process metallurgy, materials science such as micro-structural characterisation, FE modelling and data analytical approaches. You will work collaboratively with our Engineering Leads and technical staff and will have access to high performance manufacturing and characterisation facilities in the Henry Royce Institute. You will develop an insight into the technical advanced manufacturing challenges in the aerospace sector and work closely with metallurgists at DSTL