Hey /sci/, any physics/geology guys around? Have a strange question.

>>8917793
If you're knapping it, it needs to be a ceramic. Ceramics can be incredibly hard, but they're brittle. What this means is that their ultimate (breaking) strength is equal to their yield strength (the point at which they begin to deform). As a result, a collision with something ductile (iron) may bend the ductile material, but shatter the ceramic.

Your fantasy material doesn't exist. Obsidian is probably the closest real life thing, but it's going to shatter when used to strike anything.

>>8917814
I am very sure it doesn't exist.
That's more what I'm asking, what combination of qualities is most desirable?

Like, to raise its ultimate strength high enough to collide Iron without shattering what trade off would be made? Weight, difficulty in shaping, size of piece required, etc.
Trying to get a good idea for the balance of factors required.

>>8917819
A composite would likely be the best solution. Something like your picture. You'd want the main blade of the weapon to be a bit flexible, but the cutting edge can be incredibly hard. Maybe a hard glass embedded into a metal or something similar. Perhaps your blacksmiths have developed a method for a replaceable edge due to their lack of access to high quality metals?

If it can be knapped, I can't think of a way to make it withstand impact on it's own. If it could survive a collision, it probably can't be knapped.

>>8917828
I had considered a sort of saw-like composite, a metal weapon with sockets for glass parts, but I am trying to think of a way to keep the positive qualities even if it comes at the trade of being dense and heavy beyond human use.

Is it not possible that the Knapping requires high force to coincide with high strength, or is it just that it fracturing that way at all means it could never be durable enough?

File: strength_v_toughness.jpg (35KB, 450x437px) Image search: [Google]

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>>8917843
Ideally, you'd want something in the top-right corner. Ceramics are at the top, but they are closer to the left, meaning they're brittle.
You can see that metals fall a bit lower on the strength side, but have much higher toughness.
Composites enable you to get the best properties of both. I think you'd need a composite if you want something that's both tough and strong.

File: strength_v_density.jpg (33KB, 468x454px) Image search: [Google]

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>>8917843
>>8917863
Similarly, you'd want to be in the top-left for this strength vs density plot. Ceramics are pretty far to the right, meaning that they're fairly heavy for their strength.

Again, a composite is the best choice for your creation.

>>8917863
I see, I think I get the idea.
Thanks anon.
The way I was intending to use it was more of a multitool that could be used a weapon, but would often break clashing against something like a maul, but not against a blade (Unless it was approaching claymore size or a particularly heavy strike)
As the only metal that culture had access to, they really had no place in a proper battle.

Seeing the limitations I think a Composite design is more appropriate, thanks.
Some part of me is still curious about the qualities a Glass would assume if it was unnaturally strong enough to strike Iron or Steel without shattering, though, I'm guessing density.

>>8917872

Tempered glass is pretty strong. If it is absolutely free of flaws and harder than what it's striking, it might survive. The issue is that it will shatter into a million pieces if it gets any damage at all.

>>8917879
Reading up that looks well out of the technological scope I'm dealing with, I'll think about ways to create a less adept substitute on top of the composite approach, thanks.

>>8917793
If it's so hard that it doesn't break when it hits iron, how the fuck do you knap it?

Being able to be knapped and not break when hit with iron are two very conflicting properties.

No, even if it's a composite this still applies.