Harder ceramic developed for military vehicle windows
In a development that could significantly improve the strength of transparent ceramics, a group of experts from the US Naval Research Laboratory (NRL) has come up with a new way to make spinel, an armour material used in the windows of military vehicles.
The nanocrystalline spinel developed by the NRL team is said to be 50% stronger than the spinel currently used in armoured vehicles, offering the potential for stronger, more resilient armour windows and improved protection for military personnel.
To create it, the NRL research team sintered commercial nanopowders into fully dense nanocrystalline materials, using an approach called Enhanced High Pressure Sintering (EHPS).
The EHPS technique uses high pressures to simultaneously retard bulk diffusion rates, break powder agglomerates and reposition nanoparticles very close to each other to help eliminate porosity in the sintered ceramic.
While previous efforts to manufacture nanocrystalline spinel have resulted in reduced density, reduced fracture resistance or reduced transparency, the work carried out by the NRL researchers indicates that nanocrystalline ceramics can be of equal strength to microcystalline ceramics.
In tests carried out on the new-and-improved spinel, they observed no decline in density or fracture resistance.
Looking forward, the team believes their spinel could also prove useful in making more durable screens for tablets and smartphones, as well as space vehicles and extraterrestrial rovers.
