New Wire Additive Manufacturing (NEWAM)

Lead Research Organisation: Cranfield University
Department Name: Sch of Aerospace, Transport & Manufact

Abstract

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.

Planned Impact

The research outputs from LAMA will include
- New additive manufacturing (AM) or 3D printing processes for metals with greatly enhanced capability and level of control
- New concepts or feedstock material including compositions, novel shapes and new configurations
- A radically different approach to guaranteeing that component manufactured using these new processes and materials is fit for purpose in demanding structural applications, such as in aircraft manufacture
These are all highly beneficial for UK industry, including end-users of the research outputs from LAMA, as well as the whole supply chain for this new technology. End-users include many industry sectors such as aerospace, defence, energy (including renewables and nuclear), and construction. The new AM processes and materials will lead to significantly reduced manufacturing costs and lead times, combined with much higher productivity. This will make these UK industries much more competitive internationally. LAMA will also give the opportunity for UK businesses to lead the supply chain for these new AM processes, including specialist hardware, lasers, and feedstock materials; providing a major opportunity for export worldwide,
Moreover, the high level of benefit to industry of LAMA will generate significant economic benefit for the UK economy as a whole.
Societal benefits will include generation or retention of jobs in key industry sectors within the UK. The new AM process will also provide major environmental benefits as they are targeted at replacement of high consumption manufacturing methods, such as machining material out solid blocks of metal. Material savings of up to 80% are likely leading to a much sustainable manufacturing capability. Furthermore, many of these materials are highly energy intensive to produce, so that large energy saving will be achieved along with the consequent reduction in CO2 emissions.

Publications

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