metal-powder.net November/December 2013 M P R 37 special feature T he £10 million Mercury Centre is one of most important cen- tres for additive manufacturing (AM) in the world. Opened in November 2010 with funding from European Regional Development Fund (ERDF) and local investment, it forms part of the University of Sheffield’s department of materials science and engineering, one of the key research centres in the UK. It has one aim: “To accelerate the deployment of a range of innovative near net shape powder-based manufacturing processes.” According a report of the UK AM market by the UK’s Technology Strategy Board*, the global AM industry was valued at just US$1.9 billion in 2011 but with sustained double digit growth in recent years, it could be worth in excess of US$7.5 billion by 2020, based on organic growth and the continued deployment of today’s technologies. However, if current technological and commercial barriers can be overcome, the future AM sector could be worth in excess of US$100 billion per annum by 2020. That’s where the Mercury Centre comes in. While a centre of research and materials science, it works with businesses to help find ways to make AM processes commercial. “We are helping companies to adopt these tech- nologies by offering them access to our research facilities and the opportunity to explore the business benefits,” said Dr Iain Todd, from the University of Sheffield’ department of materials sci- ence and engineering and director of the Mercury Centre. “We can provide a phased approach, beginning with an initial investigation of business needs Centre for innovation and exploratory tests, through to long term-product or process optimisation.” The centre features all current AM technologies, allowing it to process a range of materials in different ways. This includes more ‘traditional’ AM technology such as additive layer manu- facture, but also new processes such as spark plasma sintering, electron beam sintering, and what the centre calls ‘2.5D printing’ – printing thin layers of electronics and biomaterials using aero- sol jet deposition. Additive layer manufacture is a proc- ess in which a component is built up in discreet layers by using a high energy heat source to melt or fuse powders. With this technology, material utili- sation can be as high as 95%, with unused powders easily re-used in the process. Aerosol jet deposition is a high reso- lution 2.5D printing technology for layer deposition onto flat or complex 3D substrates. It can print micrometric features (<10 microns), a range of layer thickness from tenths of nanometres to several microns, and create accurate vector pattern generation with excellent edge definition and low temperature processing. The process is non-contact and conformal, allowing patterning Part of the University of Sheffield, UK, the Mercury Centre is a wonderland for the AM enthusiast, featuring the most up-to-date 3D printing machines in existence in a bid to push the boundaries of this new and exciting technology. Liz Nickels paid it a visit to find out more. The Mercury Centre’s laser jet deposition high resolution 2.5D printing technology for layer deposition onto flat or complex 3D substrates.
Transcript
metal-powder.net November/December 2013 MPR 37
special feature
T he £10 million Mercury Centre is one of most important cen-tres for additive manufacturing (AM) in the world. Opened in
November 2010 with funding from European Regional Development Fund (ERDF) and local investment, it forms part of the University of Sheffield’s department of materials science and engineering, one of the key research centres in the UK. It has one aim: “To accelerate the deployment of a range of innovative near net shape powder-based manufacturing processes.”
According a report of the UK AM market by the UK’s Technology Strategy Board*, the global AM industry was valued at just US$1.9 billion in 2011 but with sustained double digit growth in recent years, it could be worth in excess of US$7.5 billion by 2020, based on organic growth and the continued deployment of today’s technologies. However, if current technological and commercial barriers can be overcome, the future AM sector could be worth in excess of US$100 billion per annum by 2020.
That’s where the Mercury Centre comes in. While a centre of research and materials science, it works with businesses to help find ways to make AM processes commercial. “We are helping companies to adopt these tech-nologies by offering them access to our research facilities and the opportunity to explore the business benefits,” said Dr Iain Todd, from the University of Sheffield’ department of materials sci-ence and engineering and director of the Mercury Centre. “We can provide a phased approach, beginning with an initial investigation of business needs
Centre for innovation
and exploratory tests, through to long term-product or process optimisation.”
The centre features all current AM technologies, allowing it to process a range of materials in different ways. This includes more ‘traditional’ AM technology such as additive layer manu-facture, but also new processes such as spark plasma sintering, electron beam sintering, and what the centre calls ‘2.5D printing’ – printing thin layers of electronics and biomaterials using aero-sol jet deposition.
Additive layer manufacture is a proc-ess in which a component is built up in discreet layers by using a high energy
heat source to melt or fuse powders. With this technology, material utili-sation can be as high as 95%, with unused powders easily re-used in the process.
Aerosol jet deposition is a high reso-lution 2.5D printing technology for layer deposition onto flat or complex 3D substrates. It can print micrometric features (<10 microns), a range of layer thickness from tenths of nanometres to several microns, and create accurate vector pattern generation with excellent edge definition and low temperature processing. The process is non-contact and conformal, allowing patterning
Part of the University of Sheffield, UK, the Mercury Centre is a wonderland for the AM enthusiast, featuring the most up-to-date 3D printing machines in existence in a bid to push the boundaries of this new and exciting technology. Liz Nickels paid it a visit to find out more.
The Mercury Centre’s laser jet deposition high resolution 2.5D printing technology for layer
deposition onto flat or complex 3D substrates.
MPR0613_AM_News_Mercury 37 28-11-13 16:53:21
metal-powder.net38 MPR November/December 2013
over existing structures, across curved surfaces and into channels. Some interesting applications of aerosol jet systems include electronic sensors and touchscreen displays, 3D printed elec-tronic devices, solid fuel and solar cells, electromagnetic interference shielding and surface biofunctionalisation of bio-medical devices.
Electron beam welding is the only technology which makes it possible to weld at several points simultaneously. The centre uses a Pro-beam electron beam welder which can perform a range of electron beam fabrication functions including welding, harden-ing, surface coating deep repair and rapid manufacture. Materials that can be currently e-beam deposited include titanium alloys, cobalt-chrome alloys, titanium aluminides, nickel based super alloys, aluminium, tool steel, stainless steel, hardmetals (including tungsten), amorphous metals, copper, niobium and beryllium.
SPS (spark plasma sintering) is a rapid sintering technique in which mechanical pressure and electric cur-rent are simultaneously applied to produce dense materials. Compared to conventional methods, SPS typically involves lower sintering temperatures and faster heating rates. This inhibits grain growth, allows better control over phase transformations and reduces energy consumption.
Metal Powder Report spoke to Dr Martin Highett, centre manager, about the range of machines at the centre. While all the machines have commer-cial potential, Dr Highett considers that laser sintering and electron beam sin-tering are the key technologies to look out for. “The Arcam [electron beam] technology builds parts with reduced residual stresses, faster build capabil-ity times, and because it operates in a vacuum, there is no oxygen pick up which could cause failure in titanium parts – crucial for aerospace and medi-cal applications,” he says. “Spark plas-ma sintering is also one to keep an eye on – we’ve had a lot of interest in that technology, although it’s pretty new when compared to laser and e-beam sintering. It has a lot of potential espe-cially in the fields of ceramics and hard metals. Moreover, the process can be done in as little as 20 minutes, which offers significant production benefits.”
According the UK Technology Strategy Board survey, by sector, aero-space is by far the largest supporter of AM technology development in the UK. The industry invested £13 mil-lion between 2007 and 2016, which in turn has levered £20.5 million of public funds for research work within academia and industry, about a third of the budget of all R&D activity. The automotive and medical sectors are the next largest supporters of research
funding, contributing £3.5 million and £3 million to lever AM research activi-ties of £6.5 million and £11.5 million.
Currently, companies from automo-tive, aerospace, defence, healthcare, green technologies and the creative and design industries have been interested in researching AM at the centre, using materials such as advanced metals and alloys, ceramics, electronic materials, polymers and biomaterials.
Focus on materialsBesides the machines, the centre has another focus – materials science. Dr Highett, like many other AM specialists, believes that a vital step in the develop-ment of AM is a proper understanding of materials science and the optimisa-tion of metal powders. “Understanding materials performance will contribute to improved product performance,” he says. “At the centre, we have a range of materials characterisation electron microscopes, including one of the world’s most powerful microscopes (JEOL R005), and a world-class reputa-tion for materials science, and we have a key part to play in how AM will be taken up over the next few years.”
The centre also offers microstruc-ture analysis, surface finish assessment, chemical composition analysis, crys-tallographic information and sample preparation. Besides scanning electron, transmission electron and optical microscopes, it also features an electron microprobe, x-ray photoelectron spec-troscopy (XPS), glow discharge optical emission spectroscopy (GDOES), a scanning probe microscope (SPM) and cathodoluminescence (CL).
AM in the UKThe centre is vital to developing AM in the UK, as Dr Highett explains. “The UK has the potential to be a big player in AM,” he says. “But currently it suf-fers from a lack of machine manufac-turers – besides Renishaw, there is no one, and the big players (such as EOS and 3D Systems) are in Germany and US.
“We also have a problem with the powder supply chain, which could be improved. But as powder suppliers
Renishaw’s 125 laser melting machine.
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metal-powder.net November/December 2013 MPR 39
special feature
become more aware of AM, we can work with them more to improve this.”
At the moment, the UK is one of the world’s leading sources of AM related knowledge and research, according to the Technology Strategy Board, with 81 organisations involved in AM research within the UK since 2007, including 24 universities and 57 com-panies. However, this could lead to a
perception that AM technology in the UK lacks a commercial focus. “This may be a barrier to wider adoption supporting the view that the technol-ogy is more focused on laboratory use than on the shop floor,” the report said. However, Dr Highett is optimistic that more in-depth materials research will result in highly commercial technol-ogy, which in term could bring the UK
to the forefront of AM. “Where the UK and the Mercury Centre can really make a difference is in reducing the barriers of commercial adoption of the technology, and the development and analysis of advanced materials to be used in the technology,” he said.
*Shaping our National Competency in Additive Manufacturing, tinyurl.com/AMintheUK
Three exquisite designs all created using additive manufacture at the Mercury Centre.
