"toughest" material

jmarcian

by terms of "mechanics" (physics, not the ones that work on your car). toughness is shown as the area under the curve of a stress strain diagram. from the we can say that this material offers a high ultimate strength, but also can strain a fair amount before breaking....
with that definition, what would you say the "toughest" material is?

also, would carbon-fiber nano tubes be considered brittle or ductile?

also, can brittle materials be as tough as ductile ones?


thanks
jared

Mapes

I'll nominate steel for toughest material (based on an Ashby chart of toughness).

Topher925

Toughness is basically the specific amount of energy a material can absorb before it fails.

I don't think you can classify nano-tubes as either since we can't manufacturer them in a pure lattice form yet.

And no, brittle materials are usually not as tough as ductile ones.


I seriously doubt that.

If I had to guess I would say Kevlar.

Mapes

Why guess? TRIP steels have a K_IC exceeding 200 MPa-m^1/2. Which Kevlar composite exceeds this?