A company established over twenty years ago to push the boundaries of metal filtration is now taking its patented technology one step further with the production of additively manufactured ceramic parts to offer greater cost savings and stronger capabilities for the foundry sector. Representing the phrase Carbon Application Technology – integrating carbon into ceramic – CAT International Ltd has a long track record of pioneering the combination of various ceramics to make composite materials with unique properties. The result has been the development and production of the CERACAT range of foam filters for steel and heavy iron casting. CAT has developed a way of layering different ceramic materials within the foam structure. The base layer is ceramic giving good mechanical strength with low material cost. Subsequent layers are blends of high alumina and proprietary ingredients developed by CAT to ensure the ‘marriage’ of dissimilar particles on firing. As a composite ceramic, CERACAT is a stable filter with a greater strength than carbon bonding alone and which can be manufactured at a much lower cost compared to zirconia.
With the rising cost of zirconia and more critically the energy cost used in production to fire it, CERACAT’s reputation has thus grown as a viable alternative that also offers a range of other benefits. From day one it has been a passion of the company’s founders, Dr Kassim Juma and Mike Leaney, to find solutions to age-old metal filtration issues. With lengthy and accomplished careers in the sector, the desire to establish a company that placed R&D at the centre of its ethos, coupled with the benefits of being a privately owned SME, appealed to the pair. Decision making is less complex and they are able to bring products to market at a quicker pace.
CERACAT benefits
There are a range of benefits of the CERACAT technology:
- High in strength.
- Thermally stable for steel and will withstand long pour durations in iron.
- High filtration affinity, e.g. the surface will chemically attract, attach and retain oxide particles.
- Lack of shrinkage during the manufacturing process compared to zirconia enables cost effective manufacture of large filters; typically up to 300mm.
- The overall density is higher than a purely carbon bonded filter but lower than zirconia meaning that in direct pour applications the filter floats readily after casting allowing free feeding path.
Whilst CERACAT is a composite, at the heart of it is a foam precursor and, with the pressing need for larger and higher capacity filters and improved consistency, the desire has long been to engineer an even better solution, with greater capabilities and ‘greener’ credentials.
The future is printed
Having developed a customer base for CERACAT, it was clear from the market that there was a demand for something a little different, Juma and Leaney recognised the need for further development. They have been identifying ways to drive innovation and further enhance the company’s product portfolio for current and new markets, leading to the investigation into adapting their in-house material technology into the concept of producing foundry consumables via additive manufacturing (AM). After reviewing the relatively easy option of printing the foam precursor or to use extrusion (like toothpaste) to build up a lattice, the blue skies thinking turned to binder jetting and carbon bonding, solutions that would eliminate the common problem when printing ceramic – huge volumetric shrinkage on firing/sintering the parts.
CAT gained funding from Innovate UK, the UK’s Innovation Agency in 2016, and initially developed a carbon bonded AM filter. But with the knowledge gained, Leaney and Juma felt confident they could take this technology further and develop a technique for purely ceramic non carbon bonded AM. Again turning to Innovate UK, the latest project involves the development of AM ceramic gating and filtration. Working with a partner to make the process a reality, CAT tapped into the Innovate grant and is working with 3D printing partner ExOne on both its gating and filtration solutions.
The result is the CERACAT 3D SYSTEM, a groundbreaking additive manufacturing technology designed to produce ceramic components tailored for the cast metals industry. The patented system is powered by the ExOne binder jetting platform, renowned for its speed and flexibility in 3D printing. Notably, regardless of the firing temperature selected, the component undergoes zero shrinkage, a distinctive feature unique to the CERACAT 3D SYSTEM within the realm of ceramic 3D printing technologies.
Through a series of research and trials, CAT now believes 3D printing of ceramic consumable parts is viable and can provide a solution to current energy efficiency, environmental and supply chain concerns. Producing ceramic filters for the filtration of liquid metal via AM rather than a foam precursor allows for design optimisation, accurate simulation and the elimination of foam decomposition chemicals being released into the environment. Leaney explains: “The cost of energy has never been higher and anything that can be fired at a lower temperature is a welcome addition. We have recently developed the first 3D printed functioning gating pieces for steel. Compared to conventional holloware our parts are one third of the weight, and are not confined to the simple shapes available currently.” Leaney enthuses: “This system revolutionises ceramic foundry consumables production. The CERACAT 3D SYSTEM utilises 3D printing’s design flexibility to enhance consumable components like filtration and gating systems. It further integrates these components with advanced casting simulation techniques, providing foundry engineers with tools to enhance casting production efficiency and quality to new levels.”
Unique material development
Based in Hixon in Staffordshire, CAT International Ltd has grown into a global suppler that has concentrated on the development of unique materials and manufacturing processes. The company’s engineering experts continue to identify new ways to develop metal filtration and to further facilitate this a ceramic freeze casting facility is also housed at the Hixon headquarters, producing parts ranging from 10g to 100kg such as filter support rings, ceramic knock off cores and filter holders. CAT has a loyal and international customer base with seventy per cent of production exported either directly or via agents, most notably to the United States.
With both 3D printed gating and filtration options, CAT is keen to continue the move towards providing more efficient and sustainable solutions to customers around the world to enable the broadening of what is ‘doable’ in cast metal. “Our business is growing,” Leaney says. “The industry recognises the work that we have already undertaken, and our customers are interested in what else we can do moving forward, but it is important that we marry our R&D and innovations with communicating and engaging with the industry. It’s important that we let people know what we have available, but even more essentially that we listen to what the industry needs. “Our customers and partners realise we are quite unique in the way we work, we have a set up that allows us to develop and adapt ideas into products very quickly, it’s what motivates us and what we enjoy doing most.”
The ethos moving forward is for further material development and foundry testing and ongoing dialogue with designers and foundry personnel to work at a pace that is suitable for all concerned. Such is the strength of their partnership that CAT International is also now acting as a UK agent for ExOne in the field of 3D printed cores and moulds and machine sales. “We have worked closely with ExOne in the development of our ceramic printing and it made sense when they asked us if we would represent them in the UK,” Leaney explains.
Watch this space!
Contact: Mike Leaney, CAT International Ltd, Tel: +44 (0) 1889 271755, email: [email protected] web: www.cat-intl.com