The ceramic dynamic

Oxfordshire-based Zircotec is well known in industry for its gas plasma spraying technology. Its coatings technology bonds thin layers of ceramic to a range of materials to improve a substrate's properties. Now, however, the firm is developing the process further to enable the production of pure ceramic components that eliminate the need for the original substrate altogether. With simple all ceramic tubular components already produced for use in very high-temperature furnace applications, Zircotec believes the spraying process offers opportunities for the manufacture of ultra light, heat-resistant parts for other sectors. In 2010 the company's move to a new factory in Abingdon that included a bespoke robot spraying booth used for high-volume runs, led to the creation of pure ceramic components. Terry Graham, managing director at Zircotec, says: "We have a project to manufacture high-temperature ceramic susceptor tubes for use in the drawing of optical fibres. In this case, we apply a zirconia-hafnia mix. These tubes provide sealed containment within the furnace and are heated to temperatures of more than 2000°C. They can withstand long periods exposed to high temperatures before needing to be exchanged." This innovation prompted the team to consider other applications for pure ceramic components. The benefits of using ceramic are well known by engineers, notably the ability to cope with extremely high temperatures. However, its brittleness often stops it being used in dynamic applications. Moving from manufacturing simple tubes to creating more involved shapes is a significant step that presents many challenges. To overcome this, Zircotec suggest a ceramic matrix technology could be used. This would essentially layer a carbon fibre composite with the ceramic material to produce complex, high-strength, lightweight parts. Taking the technology to the extreme, it might even be possible to manufacture items as intricate as exhausts, brake ducts or aerospace components. The process-specific requirements and level of tolerance control Zircotec has achieved led it to consider migration to other sectors, although Zircotec's professional motorsport presence notably in F1, means racing applications are seen as the first opportunity. "We enjoy a close working relationship with most of the F1 teams, supplying heat-resistant and anti-wear coatings," says Graham. "Through that work and F1's relentless quest to reduce weight, whilst maintaining performance, it's become evident that our ability to create pure ceramic components could be of interest to design engineers." Zircotec is only too aware of the harsh environmental challenges that an F1 car can present, such as temperature, pressure and extreme vibration. As a firm whose technology solved many issues in the nuclear field, the firm is cautiously optimistic answers can be found. The tubes are produced using a specially-constructed metal cylindrical former that enables high-purity tubes from just a few millimetres up to more than 200mm in diameter with lengths of up to 2m possible. Crucially, however, to enable the applications to evolve, Zircotec is able to manufacture other non-tubular ceramic components. He says: "Our experience means we can tightly control process parameter and feedstock to achieve a consistent, desired wall thickness, even creating interference fits for tubes to slide within each other." Considerable experience, first derived from the UK's nuclear industry has led Zircotec to pioneer the specialised process for use in automotive, motorsport and industrial coating applications. The firm enjoys a tradition since its inception for technology transfer from the first motorsport application to it most recently being used as an anti-wear coating on the winches of a yacht in this year's Volvo Ocean Race. The blend of weight and performance potential suggests its latest ceramic forming technology will be no less likely to see use in other engineering sectors.