The military is looking for new window and dome materials to replace the current multilayer glass currently used. This material need to be cheap to produce and able to withstand erosion in high speed environments. In addition this material needs to be lightweight, with no visual distortion and needs to be compatible with current night vision technology.
Now I know I've have previously spoken about transparent ceramic, but I recently discover a couple of papers written by one of my professor detailing his work in transparent spinel for applications in military defense.
Transparent spinel is actually a type of spinel called Magnesium aluminate spinel (MgAl2O4). The reason it is commonly referred to as transparent spinel is most spinel material is not actually transparent. Thanks to certain processing steps this spinel does become transparent. To create transparent spinel the spinel power is mixed with LiF (Lithium Fluoride) to aid in uniform sintering. The mix is placed in a hot press at 1550°C for 2 hours and under 35 MPa of pressure. The spinel is then cut and polished with diamonds to reveal and transparent material.
Transparent spinel offers multi-hit protection for vehicles. Spinel offers comparable protection to the current glass based armor while reducing the weight and thickness by about half. Just watch this video of an actual ballistic test of spinel vs. ballistic glass as seeing is believing.
It also has an advantage compared to AlON and sapphire which are also considered for use in transparent armor applications since it is processed at lower temperatures reducing the overall cost of production.
I think it really cool that our teachers are researching this kind of material on our campus. Keep up the good work Dr. Reimanis.