New Wire Additive Manufacturing (NEWAM)

3D打印，或增材制造（AM），已经迅速成为其他生产技术的有效和方便的替代品，这要归功于越来越多的证据表明其在缩短交货时间方面的优势；设计的灵活性和能力；减少生产浪费不仅是潜在的，而且是非常现实的。金属增材制造技术可以根据它们使用的材料的形式（粉末或电线）、热源（激光、电子束或电弧）或材料的输送方式（预先放置的床，或直接进料）进行分类。每种金属增材制造技术，鉴于其特定的性能，最适合于特定的应用。例如，预先放置的粉末床的选择性激光熔化产生精确的、净形状的组件，这些组件在设计上可能非常复杂。然而，它们的尺寸有限，成本高，构建率低。相比之下，定向能沉积（DED）工艺可以以每小时数公斤的速度制造出接近净形状的零件，并且可能不受组件尺寸的限制。到目前为止，大多数基于金属丝的DED工作都是在克兰菲尔德大学完成的，在那里，一个6米长的铝制航空结构在几天内就建成了。过去10年的研究也证明了及时（几周而不是几个月）制造大型钛零件的能力，并且成本大大降低（比用固体加工便宜高达70%），从而产生了巨大的行业吸引力。然而，制造这样的组件极具挑战性；到目前为止，它是基于工程原理的；每个新应用都需要大量的经验知识，这导致新应用和新材料的交货时间长，成本高。鉴于最终用户组合的异质性，这些功能是不断变化和众多的。因此，迫切需要建立对DED处理的科学认识；这是充分发挥其潜力并实现其应有的工业回升的关键。这种潜力可以通过结合多个过程来增加：例如，电弧和激光可以耦合到一个共生机器中，产生多个能量源配置。我们的愿景是从根本上改变大面积金属增材制造，通过开拓：-具有更高形状和微观结构精度的新型高构建率线材DED -以低成本生产净形大型工程结构-保证“首次”均匀或定制的高性能性能和结构完整性。四所大学（克兰菲尔德大学、曼彻斯特大学、斯特拉斯克莱德大学和考文垂大学）已经联合起来，用700万英镑的预算在五年的时间里完成了这个雄心勃勃的研究项目。LAMA方案由四个相互联系的项目组成：喇嘛的机舱。新的基于线材的DED工艺具有两个主要目标：同时具有高精度净形沉积的高构建率（不需要精加工）；采用主动热剖面管理，可根据沉积形状进行独立热控制。LAMA的设计室：根据最新可用的热处理制度量身定制的新线材组合物，能够产生比等效锻造合金更好的性能；它还将提供关于缺陷形成和严重程度的关键信息。LAMA的建模室：关键的基础科学和理解，采用先进的工艺和材料建模和最先进的高效率技术。将开发和实施基于物理的热学和流体流动模型，以及微观结构和力学模型。LAMA的质量室：基于物理的框架，保证成品部件的机械性能和结构完整性；包括过程中无损评价技术的发展。LAMA将建立并利用英国在基于线的DED技术方面的实质性领先优势。

3D printing, or, Additive Manufacturing (AM), has rapidly come to prominence as a valid and convenient alternative to other production techniques, this is thanks to a growing body of evidence that its advantages in terms of lead-time reduction; design flexibility and capability; and reduced manufacturing waste are not only potential, but very much real. Metal AM techniques can be categorised based upon the form of the material they use (powder or wire), the heat source (laser, electron beam, or electric arc), or the way the material is delivered (pre-placed bed, or direct feed). Each of the metal AM technologies, given its particular properties, is best suited for specific applications. For example, the selective laser-melting of a pre-placed powder bed yields precise, net-shape components that can be very complex in design. However, their size is limited, cost is high, and build rates are low. In contrast, the Directed Energy Deposition (DED) processes can build near-net-shape parts, at many kilograms per hour, and with potentially no limitation to a components' size. To date, most of the work in wire based DED has been carried out at Cranfield University, where a 6-m-long aluminium aero-structure was built in a few days. Research over the last 10 years has also proven the capability to make large titanium parts in a timely manner (weeks instead of months) and with much reduced cost (up to 70% cheaper than machining from solid), resulting in a tremendous industry pull.However, manufacturing such components is extremely challenging; so far, it has been based on engineering principles; a great deal of empirical know-how is required for every new application, leading to long lead times and high cost for new applications and materials. These are ever-varying and numerous, in light of the heterogeneity of the end-users mix. Therefore, there is an urgent need to develop a science-based understanding of DED processing; this is key to exploit its full potential and enable the industrial pick-up it merits. Such potential could be increased by combining more than one process: E.g. an arc and a laser could be coupled into one symbiotic machine, generating a multiple energy source configuration.Our vision is to radically transform Large Area Metal Additive (LAMA) manufacturing, by pioneering:- new high build-rate wire based DED with greater precision of shape and microstructure- production of net-shape large-scale engineering structures, at low cost- guaranteed 'right-first-time' homogeneous or tailored high performance properties and structural integrity.Four universities (Cranfield U., U. of Manchester, Strathclyde U., and Coventry U.) have joined forces to deliver this ambitious research programme over five years with a budget of £7M. The LAMA programme is formed by four interconnected projects:1. LAMA's engine room. New wire-based DED processes with two primary aims: simultaneous high build rate with precision net-shape deposition (no finishing process required); and independent thermal control from deposition shape, using active thermal profile management.2. LAMA's design room: new wire compositions tailored to the newly available thermal process regimes, and capable of producing properties better than the equivalent forged alloys; it will also provide crucial information regarding the formation and criticality of defects.3. LAMA's modelling room: key fundamental science and understanding, using advanced process and material modelling and state-of-the-art high efficiency techniques. Physics-based thermal and fluid-flow models, as well as microstructural and mechanical models will be developed and implemented.4. LAMA's quality room: physics-based framework for guaranteed mechanical properties and structural integrity in as-built components; including the development of in-process non-destructive evaluation techniques.LAMA will build on and exploit the UK's substantial lead in wire-based DED technology.