Xjyuk

I'm currently bouncing around ideas for a sci-fi / cyberpunk world and one of the major technologies in this universe is the manufacture and usage of metallic glass. I don't want to handwave too much away, since one of the scenes I have in mind involves a gunfight inside a factory where such glasses are made, and I was thinking of having the main characters and the antagonist's goons fighting it out using sheets of these glasses for cover as they're being moved by overhead automated cranes. I'm unsure of how to proceed with this line, as I've found a great deal of academic papers, but I can't really wrap my head around the exact properties they have. What do I need to look out for when writing about these metallic glasses both at ambient and elevated temperatures?

A metallic "glass" would be an amorphous metal or alloy. This material is commercially available in ribbon form (only, last time I checked), and is far from transparent (it looks like solder ribbon or metallic tape). It has most of the same properties as the metal it's made of, except that it has no crystal structure (this affects bending strength, for instance).

The material is made by directing a stream of molten metal at a chilled metallic roller, which cools the liquid too rapidly for crystals to form. The roller is turning very rapidly, and a combination of inertia and a sharp scraper sling the metallic glass off the roller, where it's caught and rolled in a continuous process. The commercial brand I'm aware of is MetGlas, and it's been around for decades (it's possible the company has been bought out and/or acquired competition since then).

Amorphous metal is likely to stay generally in this form, because of the cooling rate needed to prevent crystallization during cooling. You probably won't see it in large sheets or plates.

What you may see (what's been called "transparent aluminum" in the press) is aluminum oxide sheet. This is effectively clear sapphire; it's hard, very transparent, and fairly tough (but brittle -- exceed its strength by a tiny bit and it will fracture instantly, without any deformation as you'd expect from a metal). It's been used for high strength watch crystals for decades, in price ranges as low as consumer watches just above the "Timex" class.

Generally speaking, metallic glass (in terms of what you can see through) does not exist because metals have non localized electrons. This means that when light or electrons hit metal, they want to be bounced around or conducted instead of passing through.

Instead there are real-life materials which are actually very hard, clear ceramics that can offer similar protection to metals, but you can see through them. The most famous is aliglass which is a synthetic sapphire that offers similar protection as aluminum. The key difference with these materials is that they can not be deformed like true metal, but will shatter just like other ceramics if hit hard enough.

If you want a clear sculptable metallic substitute, Polycarbonate is probably your best bet. It is a very strong clear plastic which is used as a metal substitute in many industrial processes and for making see-through riot shields. While it does not have all of the same properties as metal (such as conductivity), it has a similar strength to steel.

Aliglass will be much more resistant to temperature with a melting point of ~2,000 °C vs Polycarbonate which melts at ~150°C.

If you need your Polycarbonate or Aliglass to be conductive, then layer it with graphene. Graphene is a mono-molecular sheet that conducts electrons better than gold and is several times stronger than steel. It is technically opaque, but since it is only one molecule thick, it takes hundreds of layers to actually block out light; so, it could be used to print super thin circuit boards or wiring inside your "glass" without blocking a significant amount of light.

Another option to consider is titanium dioxide doped with cobalt. It is the transparent semiconductor used in flexible screen technology. While technically crystalline it is both clear and flexible. Unto itself it is not going to have nearly the material strength of most metals, but it could be embedded in Polycarbonate or adhered to Aliglass depending on what this metallic glass is intended for. While you could probably do more with this than graphene, don't expect you metallic glass to still work after a heavy impact.

Wave them hands!

You had me at gunfight in the factory, using sheets of glass for cover. Awesome. Make your metallic glass be what your story needs it to be for the story as regards bulletproofness and other properties. It is not so farfetched. Do it up!

I like a closing scene where the protagonist enters some stuff into his phone then curls up and plugs his ears. A piercing shriek is emitted from the phone, getting higher and louder. The goons wince and look around in confusion. One of them catches on faster than the rest and bolts for the door.

Then all the glass above them shatters and rains down on them. The phone itself cracks as well - its casing is made of the same glass.