Forming new horizons

Traditional metalforming processes, such as forging and pressing, have remained relatively unchanged, in principal, for many years. With the worldwide market for the rapidly developing forging industry estimated to grow to $55.7 billion by 2010 (from $46 billion in 2005), these most conventional of manufacturing techniques are about to undergo levels of scrutiny and development never before witnessed, as part of a sustainable research portfolio, worth over £2.2 million per annum. The driving force behind the initiative is the University of Strathclyde – more specifically, the university's department of Design, Manufacture and Engineering Management (DMEM) plus its Mechanical Engineering department – in a cross-sectoral, collaborative, public-private partnership with Scottish Enterprise and industrial companies. Currently under construction, the new headquarters of the Advanced Forming Research Centre (www.afrc.org.uk) at Inchinnan near Glasgow Airport is modelled on the successful Advanced Manufacturing Research Centre (AMRC) developed with Boeing at Sheffield. Once complete, the AFRC will be better able to further its R&D activities relating to processes and techniques that include: metalforming processes such as forging, pressing and super plastic forming; primary techniques, such as plastic deformation and flow; supporting technologies, like heat treatment; supply chain issues, including materials quality and purity; secondary processes, such as die manufacture and lubricant application; and tooling design. Managed by the university, the AFRC will support the design and manufacture of new products, including components and structures for aircraft wings and bodies, engines, cars, ships, medical devices, power generation equipment and wind turbines. The goal is to make the UK's engineering sector even more competitive globally by delivering advanced products to the marketplace quicker and more cost effectively. The turnover of the UK forging and forming industry is, incidentally, around £2.1 billion, representing a gross value added of £0.8 billion. Image: An 'industrialised' Strathclyde university crest TWO MAIN AIMS "The research programme will have two main areas," explains operations director William Ion, "a core programme that will be funded and directed by our members, as well as research on a contractual basis from both research councils and commercial organisations. "The AFRC has been two years in the concept stage," he continues. "The idea was originally put forward by Rolls-Royce, which was keen on the AMRC model at Sheffield. Since then it has taken a lot of political discussion and persuasion from all of our members to secure public sector funding from Scottish Enterprise." Mr Ion suggests that the establishment of AMRC, and now AFRC, has already led to the creation of a new acronym: AXRC. "The AXRC network is a term starting to be used more and more," he says, "with 'X' denoting the core focus of the facility. Other centres will join the AXRC network as and when they launch." Supporting fundamental and applied research in forming and forging, AFRC activities will vary from blue-sky projects laying the foundations of future forming technology, to troubleshooting established industrial processes. In fact, its first projects have already commenced (funded directly by industrial contracts) using existing staff and facilities within the university. However, from spring 2010, researchers will be able to exploit the new £25 million purpose-built facility, which will be furnished with technology making it the envy of metalforming shops the world over. Of the £25 million (being invested over five years), £16 million is coming from Scottish Enterprise, which will fund both the new facility and the capital equipment housed within (approximately £6 million). The remainder is coming from other sources, such as the Engineering and Physical Sciences Research Council (EPSRC) and, additionally, AFRC members. Among the intended purchases will be various industrial forming machines, including forge, servo and SPF presses, state-of-the-art metrology and metallurgy equipment, and workshops with electro-mechanical and computer simulation facilities. The technology will allow AFRC to research topics that take in both incremental change and disruptive technologies in materials and manufacturing processes related to hot and cold working in metals and composite materials, all under the guidance of professor Jeff Brooks, who was appointed AFRC research director on 1 June 2009. Image: An artist's impression of the new facility NEAR NET ON THE AGENDA "Around 20 years ago, forging followed by finish machining was the accepted norm for many precision, yet mid-volume components," says Prof Brooks. "The advent of high speed machining and 5-axis machining introduced a level of flexibility into the process that allowed engineers to decide final component design much later in the process. However, these processes are today being squeezed as cost becomes a bigger and bigger factor. Coupled with high raw material prices, the focus once more is on near net shape, but this time with certain provisos. Part of our remit is to develop processes that are not just closer than ever to net shape, but that also offer benefits such as improved quality, reduced time to market and greater tool life." Prof Brooks indicates that some reasons for the shift back to net shape come from poor experiences in low-cost economies, where insufficient quality, rising wages and unfavorable exchange rates have driven many western manufacturers back onshore. The core forming technologies housed at the AFRC will centre on areas such as SPF, forging, roll forming and incremental forming, all of which will be divided into both hot and cold process workshop areas. The AFRC will push boundaries that include: greater press control; improved instrumentation; enhanced die materials and coatings to provide extended and predicable tool life; improved material characterisation and understanding for modern engineering materials, including inter-metallic and metal matrix composite structures; better process modelling and simulation; greater automation; improve control/use of energy/heat, possibly through the deployment of industrial microwave technology; and, ultimately, lower process and component costs. As part of the work performed by Prof Brooks' team, specific equipment will include an X-ray diffractometer to identify crystallographic phases present within a range of materials and also examine grain texture and residual strain. Also on the list of intended capital equipment purchases are: an automatic micro Vickers hardness testing machine with Knoop attachment; a mechanical testing machine to carry out tensile/compressive, creep, fatigue, stress rupture and fracture mechanics characterisation; a scanning electron microscope; and an optical microscope for metallography. Image: The Strathclyde university crest, for real QUALITY AT THE HEART "Quality is at the heart of many modern forging and forming demands," says Prof Brooks. "A couple of decades ago, a forged airfoil would command a tolerance of around 0.5 mm. Today, tolerance demands for an identical forged component are much more like 0.12 mm. On top of this, forgings are more complex, in terms of both shape and cross section, while harder, stiffer and tougher materials introduce further challenges." The beneficiaries of the AFRC's efforts will be its members, which range from blue-chip multi-nationals, such as Boeing, Mettis Aerospace and Rolls-Royce, through to specialist suppliers such as Mitutoyo (01264 353123), Renishaw (01453 524524) and Fanuc Robotics (02476 639669). A broad base of supporting industry enables the AFRC to engage with multi-scale problems in which researchers relate macro process parameters (such as tool geometry and loading rates) to micro-characteristics of form material (such as grain size and structure). Significant interest in membership is already being shown by a number of additional UK and international companies. There are two levels of membership. The higher level (Tier One) is intended for companies with a direct interest and major return opportunity. This category will secure a full seat on the board that directs the research programme. The second category of membership (Tier Two) is designed to ensure supply chain companies, key technology providers and other partners can participate. "We are really pleased with the cross-section of Tier One members we already have on board," says Mr Ion. "However, we will be actively seeking others to join in the near future, perhaps to include a press technology supplier and a prominent materials developer. We anticipate eight Tier One members and 10 Tier Two members within the space of five years." TECHNOLOGY PIPELINE Research topics will be identified by members, with the AFRC expected to deliver a proven and rapid 'technology pipeline' from concept and demonstration through to commercial exploitation. New standards will be set for the design and forming of high integrity, high value added products. "Our participation in the AFRC provides us with opportunities to help develop advanced forming and forging technologies that yield higher quality, lower-cost components for current and future aerospace systems," says Ricky Martin, fabrication technology leader at Boeing Research & Technology. "The AFRC is a good example of how universities can work with global companies to bridge the gap between fundamental research and industrial application," adds Professor Jim McDonald, principal of the University of Strathclyde. The AFRC is set to be a beacon for engineering and manufacturing excellence. Eventually it will house up to 60 people. Around 45 will be dedicated AFRC staff, with the remainder made up of PhD students and representatives from members, some of whom may be sited at Inchinnan permanently. There is no doubt that the University of Strathclyde is well placed to manage the AFRC. It is building on 25 years' experience in the sector and is currently managing the largest forging and forming contract under the EU's Framework 6 research programme. The creation of the AFRC will allow full participation from other specialist institutes and universities to ensure that the most appropriate support is brought to bear in pushing forming and forging boundaries. Super plastic forming The super plastic forming (SPF) facility at the AFRC will consist of a 1000°C platen measuring 1.5 m2. SPF is based on the theory of super-plasticity, whereby sheet material can elongate beyond 100 per cent of its original size. It involves placing a sheet of, say, titanium over a cavity, applying heat and using pressurised argon to force it into the cavity. The advantage is that large and complex workpieces can be formed in a single operation. This is conventionally challenging in material such as sheet titanium, which demonstrates high levels of spring-back and a general resistance to deformation. At present, the only drawback to SPF is its relatively slow forming time, an issue that the AFRC is set to address. Apparently only three UK companies are currently exploiting SPF. As such, the AFRC will seek to further this low maturity process, broaden its benefits and widen the appeal and accessibility of SPF. First published in Machinery July 2009