3 ms·
See section on "compressive strength".
by fhood 5y ago
See section on "compressive strength".
- jazzyjackson 5y agoDiamond has a very high compressive strength, but if you drop one it will shatter, it is brittle. Since this new material has similar hardness & strength, I would assume it is similarly brittle.
- jacquesm 5y agoBrittleness is arbitrarily defined as the ration between tensile and compressive strength so GP has a point (high compressive strength usually indicates a more brittle material), but without knowing the tensile strength it remains to be seen if it is more brittle or less brittle than say diamond.
- harpiaharpyja 5y agoDiamond is quite brittle so I think to the point of the discussion, it's likely a brittle material even if it's somewhat less brittle than diamond.
- beerandt 5y agoDiamonds are actually tricky, because their practical brittleness is mostly due to breaks in the lattice caused by impurities. The lines of weakness are defined as cleavage, and diamonds will typically cleave along those lines when the break. So there's a bit of ambiguity between the actual brittleness of the pure carbon structure and the practical brittleness where breaks in that structure naturally exist.
- zardo 5y agoDoes that mean diamonds might have ductile fractures if they were flawless? Or just that they would be stronger?
- beerandt 5y agoI don't think a single part of your comment is true. ASCE, ASTM, and other professional orgs have non-arbitrary definitions. They are all versions of some measure of deformation at ultimate strength, but don't correlate to that strength value. Crackers are brittle. Structural steel is not.
- jacquesm 5y agoYes, but this is an informal discussion, so that ratio actually serves a purpose unless you want to attach a complete course in materials science, it's 'good enough' for this level of discussion and sheds some light on why it is a thing to begin with. Oh, and just to fortify this comment here is a reference: https://subsurfwiki.org/wiki/Brittleness https://subsurfwiki.org/wiki/Brittleness
- deleted 5y ago[deleted]
- beerandt 5y agoStrength is unrelated to brittleness. Brittleness is a measure of plastic deformation at the (ultimate strength) breaking point. Eg, diamonds, cast iron, and saltine crackers are all very brittle. Resilience and ductility are related technical terms, but not quite opposites.