Ultrathin antirust coating that works at 1100°C
Hexagonal boron nitride (h-BN), often referred to by the somewhat catchier title of ‘white graphene’, has been found to prevent rusting – even at temperatures exceeding 1000 degrees Celsius.
The discovery was made by a group of researchers based at Rice University (Texas), led by Professor Pulickel Ajayan and Professor Jun Lou. The fruit of their research trumps existing anti-oxidation technologies due to its potential scalability. It is hoped that huge sheets of h-BN can be created using scaled-up chemical vapor deposition (CVD).
‘Everybody has been talking about these materials for electronic or photonic devices, but if this can be realized on a large scale, it’s going to cover a broad spectrum of applications,’ said Lou, an associate professor of mechanical engineering and materials science.
Its heat-resistant, ultrathin protection suggests applications in turbines and jet engines but it is also suitable for use in other demanding environments, such as underwater. White graphene’s extreme thinness and exceptional lightness provide obvious advantages. However, the issue of durability must be addressed and an application-specific, optimum thickness needs to be calculated.
‘What’s amazing is that these layers are ultrathin and they stand up to such ultrahigh temperatures,’ Ajayan said. ‘At a few nanometers wide, they’re a totally non-invasive coating. They take almost no space at all.’