The future of blade technology

[kisak]

Originally Posted by Jim McDougall

I am not clear on exactly how long ago the secrets of Damascus steel were rediscovered by metallurgists in the west, or exactly how successful this was done,

A while back I had the chance to search for material on wootz in a rather large database of scientific papers. Amongst what little I found was one account of Indian steelmaking procedures, describing the crucible method, from 1829, and one chemical analysis of the composition of wootz from 1852. So while we might only have arrived at our current level of understanding quite recently (thanks to Verhoeven et.al), it seems a basic idea has been with us for quite some time.

On the composition of wootz, or Indian steel • SHORT COMMUNICATION
Journal of the Franklin Institute, Volume 54, Issue 3, September 1852, Pages 212-213
T. H. Henry

On the manufacture of iron and steel (Wootz) in India: from "A journey from Madras, through the countries of Mysore, Canara, and Malabar" • SHORT COMMUNICATION
Journal of the Franklin Institute, Volume 7, Issue 1, January 1829, Pages 7-16
Francis Buchanan

Originally Posted by fearn

I'm waiting to see metal glasses go mainstream. /.../ based on metallic recreations of shells and teeth-type biocomposites

Isn't there a problem with those where they tend to behave in a rather brittle fashion, despite being quite tough on paper? I seem to recall hearing that they had a nasty tendency of focusing all the stress in one point, leading to that point failing while the rest of the material was basically just sitting there and twiddling its thumbs.

As for those biocomposites, I'm not entirely familiar with them, but there's a vague memory in my head of them using extremely thin layers of the material to get the properties? In that case, it actually sounds pretty close to the bainitic steels, as those seem to obtain their properties from the aggregates of extremely thin crystal plates. (This would seem to be a very different concept from the type of folding traditionally done to steel in many parts of the world, with very different results.)


Regarding the monomolecular edges mentioned by a few people here, one thing to remember is that molecules vary greatly in size. Diamond crystals are actually single molecules, and can reach quite a few centimetres in size (metals on the other hand aren't molecular at all, but we can create single metal crystals of impressive size, often for turbine blades, the lack of grain size hardening effects might make such unsuitable for blades though).

I also wonder if there might not be a point where the exact width of the outermost edge doesn't really matter all that much any more, as the rest of the knife needs to be pushed into the material as well to the depth of the cut.