View Full Version : Metal Alloy for Armor

08-22-2012, 04:44 PM
I need a metal alloy that doesn't rust and is very strong. Something a medieval/renaissance-era culture would be unable to create on their own.

My setting is a long-abandoned colony world, and I want them to have a limited supply of a particular metal that's been scavenged and passed down from the original colonists. They know the metal was created by their ancestors, but they have no idea how to make it themselves. All they can do is melt it down and reuse it. This makes it quite valuable, especially because it doesn't rust and is very lightweight and strong. The king's personal guards wear armor that's made of this stuff, and their swords and arrowheads may or may not also be made of it, depending on whether that's practical. (I have no idea if the type of metal that makes a good weapon would also make good mail.)

I was thinking steel, but apparently that's been around for centuries. Is there any sort of modern metal that I could use? Or do I need to just make something up?

08-22-2012, 04:47 PM
Stainless steel, maybe some titanium; look up shark suits

08-22-2012, 05:11 PM
Not an alloy, but... titanium? It wasn't discovered until the end of the 18th century, if memory serves, and even then it took until 1910 to produce pure titanium, and until the 1930's it was only really used in labs. Its melting temperature is a little higher than iron, but not (I think) beyond the capabilities of the forges of that era. Titanium is strong and lightweight - it's used for aircraft frames, racing bikes, anything where you need the strength and rigidity whilst keeping mass to a minimum. Also, the procedure to actually produce it from ore is complex, requiring chemical processes that are definitely beyond your medieval culture's capabilities; probably beyond their understanding entirely, so even if they could recognise the ore it's unlikely they'd be able to get any actual metal out of it.

As for uses, titanium is resistant to cracking and corrosion and very rigid, so it should make decent armour. Lightweight, tough, and low-maintenance. It's also silvery and can be polished, so a royal guard would look nice and shiny, if needed. Unfortunately, titanium is more brittle than steel and doesn't respond as well to heat treatment, so it'd make terrible swords. It might work for arrowheads though. A sword needs to hold an edge under prolonged abuse, while taking blows from multiple directions; an arrowhead needs to be sharp once, for less than a second, taking once solid impact in a single direction. This is why flint can work for arrowheads but not swords. A titanium arrowhead would be a shade lighter than a steel one, which might result in better range (depends if the arrowhead is a large fraction of the arrow's overall weight; I don't think it is). The increased rigidity might also give it better armour-piercing ability, depending on (among other things) how much a regular arrowhead deforms on impact. The lower mass would reduce energy assuming it hit at the same speed as a regular arrow, but when you consider that the lower mass would also allow the same bow to shoot a titanium-headed arrow a shade faster, and in the kinetic energy formula, velocity is squared... Then combine that with the greater rigidity of the arrowhead... I don't know a great deal about the physics of impacts like this to comment much, but my instinct is that it would be a little better than steel arrowheads at punching through armour. I seem to remember something about anti-tank weaponry that used penetrators made of titanium or titanium carbide, so perhaps it does work.

08-22-2012, 05:35 PM
I'd go with a stainless steel. It seems simple enough to us, but it would be a miracle metal to someone in the Middle Ages.

Btw, you don't want armor to be too light as the mass is important in absorbing some of the energy of the blow.

08-22-2012, 06:26 PM
Thanks for the quick replies! I'll do some research, but titanium sounds perfect. I considered stainless steel, but it doesn't quite fit what I'm looking for.