From a technical standpoint, titanium alloys are highly suited for ballistic protection applications. The key is the amount of protection that a material can provide per unit of weight, as any person wearing the armour needs to be able to still move around easily. In this case, titanium can provide weight reduction for the same protection compared to other aluminium and steel alloys. See this nice little presentation I found that gives some comparisons.
I would imagine they are using a high performance titanium alloy, likely Ti-6Al-4V, as if you were looking for something cheap, you would just use a steel alloy anyway and not bother with lower grade titanium alloys. The key competition would be ceramic-based armours, which allow a lower weight again from what I understand. However, they are also more expensive, and the processing means they are generally small flat plates held together in a vest to form an overlapping scale type pattern.
So I don’t think there is really anything super special going on here materials wise. The first announcement did mention surface treatments, though. So they are likely performing some surface treatments that turn the surface layer into a ceramic, thereby improving the blastic protection by blunting/shattering the projectile. A nice little thesis out of the US Navy college below (with poor data presentation) looks at the effect of different titanium/ceramic combinations if anyone is interested.
https://apps.dtic.mil/sti/pdfs/AD1060002.pdf
The expanded scope in this announcement is maybe some design changes Lightforce wants to explored or different thicknesses or treatments that require more samples. It seems to be progressing well on AML3D’s side. In a recent interview, Andrew Sales mentioned that it was delayed on Lightforce’s end.
Not a lot of experience in ballistics myself, but I am a soon to be PhD qualified metallurgist.
AL3 Price at posting:
20.0¢ Sentiment: Buy Disclosure: Held