Peter Wagner examines a new material that, temperature-wise, sits between cheaper plastics and high-end ceramic composites
Christoph Hofer, senior business development manager at Isovolta, believes he has spotted a niche in the composites market. He says, “If you look at the transport sector, there is an increasing need for an easy-to-handle material that is able to withstand higher temperatures, up to 900°C. Normal thermoset composites such as those using phenolics or epoxy resins tend to fail around the 250°C mark, and the more thermally stable solutions such as PEEK are expensive. At the other end of the scale, around the 1,000°C zone, ceramic composites can perform well but are expensive and not easy to manufacture. So we developed a material to sit in the middle.”
The new product, Cerapreg, is a combination of silica fibres with a silicon/aluminium oxide blend matrix that produces a low-density composite that is lighter than metal. It is aimed at mechanically loaded products that need to operate consistently in harsh environments – items such as exhaust components, for example.
Hofer continues, “We use a very short two-step sintering cycle so we don’t compromise the integrity of the matrix. There’s a slim window in the temperature-resistance curves of both the matrix and the fibres that allows us to blend these two materials without having to worry about reducing the mechanical strength.”
The material starts life as a water-based ceramic slurry. The design brief stated that it had to be easy to handle on-site and must not be toxic. No special equipment should be required to use it, and staff familiar with working with any other polymer composite should be able to use it without special training.
Hofer adds, “We are very much aiming this at a niche market. We feel the customers will be in the high-cost, low-volume industries such as racecar builders or aerospace OEMs and suppliers. These are markets where there is always a desire to make everything lighter without compromising on structural integrity.”