A Finnish researcher may have discovered a method for producing glass with alumina that is far more flexible than conventional glass.
According to research published by Erkka Frankberg at Tampere University in Finland, conventional glass has not found a wider range of applications due to its highly brittle nature. Conventional glass is formed by rigid tetrahedral structures that tend to propagate sharp cracks. Because the silicates in traditional glass have no effective way to dissipate force, the force applied to it finds weaknesses in the glass, ultimately leading to failure and shattering it.
Frankberg and her colleagues realized that the key to making glass stronger would be to blunt the tips in the glass as they crack, making the glass more ductile and resistant to breaking under force. This led them to produce a new type of glass using aluminium oxide (alumina) in place of silicon oxide (silica).
Per the researchers, the new glass made with alumina (amorphous alumina) consists as a crystalline form that can be irreversibly deformed at typical room temperatures, making it difficult to manipulate. However, experiments with amorphous alumina showed that its molecular bonds were 25 times more likely to reform after breaking than those in silica glass. Not only does it make alumina glass more impact resistant, it allows the molecules to direct the stress through ductile channels, blunting any cracks made in the process. As a result, the alumina glass is able to handle higher strains than silica glass and can be stretched by up to 100 percent of its elongated length.
Frankberg tempered the discovery’s excitement by saying the tests were made upon defect-free amorphous alumina, which is likely commercially impossible with current technology and practices. Nevertheless, she says this is research that may help to lay the groundwork for scientific inquiries into a variety of oxide glasses in the future.