What is the Toughest Material? Carbon-Fiber Nano Tubes & Brittle Materials

[jmarcian]

"toughest" material

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

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?