In this feature, BATTLESPACE looks at GKN Aerospace’s development of Additive Manufacturing Technology as a key part of its future technology development
One of the key aims of GKN’s future growth centres around the development of the Company’s expertise in Additive Manufacturing (AM) technologies, a technology which GKN has made a number of key developments since 2012.
GKN Aerospace is involved in research and development programmes to progress a variety of techniques covered by the general term ‘Additive Manufacturing’ (sometimes also referred to as ‘3D Printing’). Additive Manufacturing is the process of iteratively creating components layer by layer. It is not a single technology or process but a generic term to describe a whole range of processes each appropriate for different applications and materials.
These technologies promise a paradigm shift in engineering design allowing previously impossible or uneconomical geometries to be achieved and opening up completely new design possibilities for components and systems. Because AM processes effectively create the material as they make the part, these processes open up the potential of material science. In the immediate future this means we will be able to use new materials that we cannot currently manufacture into the required complex shapes. Eventually, this will allow us to develop totally new materials and functionally graded structures.
GKN Aerospace has invested heavily in testing and standardising processes and materials to produce quality procedures which the company can use to obtain aerospace qualification for AM produced components. This is well underway. GKN Aerospace has AM manufacturing in production and parts are flying today. The company expects the number of parts being manufactured to increase significantly over the next 2-5 years
In parallel, the company is developing a thorough understanding of the design freedom afforded by AM, of the processes and materials involved, and of what will be required to produce the entirely novel parts that will be used in the next generation of aircraft.
The scope of the company’s work extends across the whole value chain, taking in: new materials; process capability and development; new applications; new components; and part qualification. GKN Aerospace has established 4 additive manufacturing centres of excellence globally and is also leveraging broader GKN-wide expertise, including extensive capabilities in. powder metallurgy to progress this development work.
GKN Aerospace activity is focusing on a number of AM technologies including:
- Large scale deposition – which can produce larger scale near net preforms which require much less machining than traditional forgings or billet, as well as future large optimised structures and is suitable for applications such as medium sized components too large for powder bed right up to large bulk heads, wing ribs and spars.
- Small scale deposition which produces smaller near higher detailed net shapes and can be used to directly deposit additions such as bosses to larger structures or be used for the modification of and repair of high value engine and airframe components.
- Laser powder bed which produces intricate, highly complex smaller high value components.
- Electron beam powder bed which produces very near net shape and structurally optimised, small to medium sized engine and airframe prismatics.
AM processes promise to revolutionise the manufacturing of aerospace components by enabling new, efficient, lightweight designs to be created, and new, tailored and higher performing materials to be adopted. Simultaneously these processes will drastically lower the levels of material wastage associated with the current, dominant, ‘subtractive’ processes – based around machining a part from a solid. Additive processes will reduce the amount of time and energy required in manufacture and lower the carbon emissions produced. They will allow material optimisation throughout the component and, most significantly, they will flip the established ‘cost/complexity’ equation that manufacturing, across every sector, is used to working with – these processes will enable design optimisation and will allow us to introduce a level of complexity in each structure that is either not cost effective to manufacture – or simply not achievable – today.
GKN Leads Horizon R&D Programme
GKN Aerospace announced in July 2014 that it was to lead a consortium of UK companies in a 3½ year, £13.4 million R&D programme called Horizon (AM) that builds on GKN Aerospace’s extensive and fast-developing additive manufacturing capability.
The Horizon (AM) team includes GKN Aerospace, Renishaw, Delcam, and the Universities of Sheffield and Warwick. The programme is backed by the UK’s Aerospace Technology Institute (ATI).
Horizon (AM) will take a number of promising additive manufacturing (AM) techniques from research and development through to viable production processes, able to create components that could be as much as 50% lighter than their conventional counterparts, with complex geometries that cannot be cost effectively manufactured today. These new processes will unlock innovations in low drag, high-performance wing designs and lighter, even more efficient engine systems – and lead to dramatic reductions in aircraft fuel consumption and emissions.
The programme will focus initially on using AM techniques to create near net shape parts which require very little machining. This will dramatically improve the ‘buy to fly’ ratio of the part by reducing the considerable cost in time and material wastage associated with the conventional machining of metal forgings. With material wastage as high as 90% for some parts, a significant reduction here will also provide major environmental benefits.
Partnership With Arcam
Building on this expertise, in March 2015 GKN Aerospace entered a strategic partnership with additive manufacturing specialist, Arcam AB, to develop and industrialise one of the most promising of the new ‘additive’ processes to meet the needs of the expanding future aerospace market.
The joint technology development (JTD) partnership is focused on developing electron beam melting (EBM), a process in which metal components are built up, layer-by-layer, using a metal powder that is melted by a powerful electron beam. EBM is able to produce very precise, complex, small to medium-sized components that require very little finishing.
As part of this agreement, GKN Aerospace has ordered two ARCAM Q20 EBMmachines to be installed at GKN Aerospace’s Bristol, UK additive manufacturing (AM) centre. GKN Aerospace and ARCAM engineers will then work together to create the next generation of EBM equipment, able to manufacture complex titanium structures at the high volumes required to meet future demand.
GKN Aerospace Commences Additive Manufacturing Research
GKN has long been a pioneer of Sinter Metals technology, a process which now forms one of the key legs of GKN’s technology. GKN Sinter Metals offers its customers a wide range of products, technologies and services – extending from engineering and design consultation, to product development, testing and the manufacture of the most complex components.
Sintering is the process of compacting and forming a solid mass of material by heat and/or pressure without melting it to the point of liquefaction.
Sintering happens naturally in mineral deposits or as a manufacturing process used with metals, ceramics, plastics, and other materials. The atoms in the materials diffuse across the boundaries of the particles, fusing the particles together and creating one solid piece. Because the sintering temperature does not have to reach the melting point of the material, sintering is often chosen as the shaping process for materials with extremely high melting points such as tungsten and molybdenum. The study of sintering in metallurgy powder-related processes is known as powder metallurgy. An example of sintering can be observed when ice cubes in a glass of water adhere to each other, which is driven by the temperature difference between the water and the ice. Examples of pressure-driven sintering are the compacting of snowfall to a glacier, or the forming of a hard snowball by pressing loose snow together.
Using its Sinter expertise and technology GKN Aerospace announced in April 2015 collaborative research to create additive material for aerospace
GKN Aerospace is to lead a 3 year, £3.1 million, collaborative research programme to develop titanium powder specifically formulated and blended to meet the needs of additive manufacturing (AM) of aerospace components. The programme, called TiPOW (Titanium Powder for net-shape component manufacture) will also commence work developing the techniques and equipment that will produce the powder consistently, in quantity and at a lower price than today’s material.
The TiPOW programme is backed by the UK’s Aerospace Technology Institute (ATI) and the country’s innovation agency, Innovate UK. Consortium partners include UK companies Phoenix Scientific Industries
Ltd and Metalysis and the University of Leeds. As programme leader, GKN’s aerospace business will also draw on the expertise of the GKN Powder Metallurgy division a world-leading supplier of metal powders and precision engineered components.
Today additive manufacturing uses alloys and powders that have not been developed for these processes and so are not optimised for this environment. Together the partners will investigate developing titanium alloys and powders with the characteristics that are specifically suited to AM. They will then define the production methods that will produce AM-designed materials to ensure cost is minimised whilst production quality, quantity and consistency all meet the rigorous standards required by aerospace. The TiPOW programme will also explore effective re-use and recycling of titanium material, and a study of potential applications for the recycled material.
The TiPOW programme forms one element in a major AM research and development initiative across GKN, and will run alongside another GKN Aerospace-led, ATI supported, programme called ‘Horizon (AM)’. This programme aims to take a number of promising AM techniques through to viable production processes. Five dedicated AM development centres have been established in North America and Europe each clearly focused on progressing specific additive processes and technologies.
GKN Aerospace and Sheffield University establish RAEng research chair to progress additive manufacture (AM)
It was announced in July that GKN Aerospace is to sponsor a five year Royal Academy of Engineering (RAEng) research chair, based at the University of Sheffield. The chair is focused on harnessing and developing the extraordinary potential of additive manufacture (AM) for aerospace and other high value industrial sectors.
The GKN Aerospace RAEng chair in Additive Manufacture and Advanced Structural Metallics will have three fundamental aims: to assist in the industrialisation of the current state-of-the-art technology as GKN moves towards production; to develop the required technology to enable the integration of materials and processes, extending the application of AM in the short term; to create entirely innovative processes and materials that will carry industry well beyond what is currently possible.
Russ Dunn, Senior Vice President Engineering & Technology, explains: “AM technologies promise a paradigm shift in engineering design and materials. We will be able to create previously impossible or totally uneconomical shapes, with little or no material wastage, and in the longer term we will be able to develop completely new materials and structures fully optimised for the role they perform. This new chair will build on GKN’s existing developments in additive manufacture and will sit at the heart of work to ensure UK industry continues to be a pioneering force in this global revolution in engineering.”
Professor Iain Todd has been nominated for the Chair. Professor Todd is recognised as a leading academic researcher in the fields of novel processing and alloys. He has led research into additive manufacture at the University of Sheffield since its commencement in 2006 and has been a driving force in the growth of its world-leading manufacturing research facility, The Mercury Centre. The current university AM research portfolio includes work on the Aerospace Technology Institute (ATI) supported, GBP15M Horizon Programme, led by GKN Aerospace, as well as collaborative research with organisations such as the Culham Centre for Fusion Engineering and CERN.
Professor Todd comments: “I’m delighted and honoured to be appointed to this prestigious role and look forward to working with GKN Aerospace and the Royal Academy of Engineering in promoting, researching and helping to drive this hugely exciting and disruptive manufacturing technology forwards. This is a very exciting time for advanced manufacturing and materials research in the UK. My role will be to strengthen the link between industry and academia in these fields and to transfer the engineering and scientific breakthroughs at the University level to industrial practice helping to drive productivity and competitiveness.”
Professor Ric Parker CBE FREng, Chair of the Royal Academy of Engineering Research and Secondments Committee, says: “We are delighted to support this Chair as part of the University of Sheffield’s ongoing and productive collaboration with GKN. Additive manufacturing is an important area for research and development, which has enormous potential to improve industrial processes and UK productivity in the future.”
GKN Aerospace, the University of Sheffield and the Royal Academy of Engineering will make a combined investment worth GBP1m to support the chair over the five years, with the GKN Aerospace investment including funding for an additional 10 PhD students to support Professor Todd and the team of over 20 senior research staff already operating at the university.
GKN Aerospace has an established relationship with the University of Sheffield, most recently through the Horizon AM programme where the university, Renishaw and Delcam are partners. GKN Aerospace also supports PhD and EngD programmes at the university and provides student placements.
GKN Aerospace is also the industrial sponsor of a five year RAE Chair based at the University of Bath and focused on advancing the manufacture of aerospace composites.
There is little doubt that GKN is now an established world leader in AM technology developments.
Dr Rob Sharman, Global Head of Additive Manufacturing of GKN Aerospace, said: “We have spent the last few years building our knowledge, credibility and capability of this game changing technology. With our network of partners in the supply chain, academia and customers we are now at the exciting point where we are industrialising; moving from research and into production.”