The text book "Microstructure of Steels and Cast Irons" by Prof Madeline Durand-Charre has a section on the history of steels usrd in swords and sword making .
She discribes the various types of sword steels used indifferent regions. Regarding Damascus Steel swords. There are two types - one she calls modern damascus and authentic damascus. The basic difference is that modern (including early fake authentic) is made using layers of hard (high carbon) and soft (low carbon) steel bars that are forge welded together, folded, and forged into many very thin layers of hard/soft steel. (I have a couple of knives made with this process and it has some interesting properties.- below)
Authentic damascus steel is made from one piece of "wootz" steel (carbon approx 1.3% to 1.9%, a very high carbon steel.) This steel is very difficult to forge - too hot and it cracks, too cold and it cracks. Forging too slowly in the correct temperature range results in the hard microconstituents (iron carbide) converting to graphite But when heated and forged and heated correctly, it forms fine layers of alternating fine bands of hard and soft components that give the sword its properties. Apparently, some European sword smiths learned how to make such steels in the 16-17 century. However, as swords became less important in warfare, the need for the performance dropped and the very high cost of the process resulted in the process being lost. Forged welded damascus blades had similar appearance (status) and cost less.
There are a number of studies of authentic damascus going on different universities, characterizing the microstructure and trying different methods to reproduce it. And since these are university studies, the intent is to understand the microstructural reactions taking place. There are a few different theories that have some experimental verification. But there is still disagreement as to the methods used historically.
I've used one of my modern damascus knives for wood carving. I've examined the blade on a metallograph at work both after sharpening and after carving wood. When sharpened and stropped, the edge is smooth (and very sharp), since the hard/soft layers are not parallel to the sharpened edge after using the knife to carve wood, the edge is microscopically serrated (and still sharp). Other carving knives I have need to be re-honed after similar amounts of carving.
Fair cop. My history book missed out some details. I just thought the way they did the heat treatment was very cunning.
The question now is: If at some point we knew how to make something and now we don't, does it matter at all if we understood the underlying processes deeply or not? Call it "lost technology" or "lost craft" who cares? We are still sitting in the dark with no wheels on our wagon and no way to smite our enemies with sharp instruments.
Of course we are curious to find out more about how and why things work. It's amazing though how far we came without knowing anything much.
Well, we have been pondering such a dilemma of loses about what we once knew ever since the library at Alexandria burned.
Some people see the world as a cup half-empty, others see it as a cup half-full.
The idea that we might never get back to the moon due to lost technology is ludicrous. ... an attention-getting device intended to launch loyal patriots into a bunch of NASA jingoisms so that a newpaper can up its circulation.
There is such a term as research, isn't there? We are constantly looking back and revising what we know.
Not just that we cant go to the moon any more - we even can't produce a decent sword?
@jazzed,
We can still make plowshares.
Actually it's much, much worse than that.
Following the collapse of civilization as we know it under the weight of the inevitable third world war, itself brought on by fuel, food and other resource shortages and the ridiculously huge population we have that is busy laying the planet to waste, we won't even be able to aspire to the level of the iron age or the bronze age.
Why?
Because all the easy to get useful minerals and ores are long since exhausted.
Of course we have no animals left so forget about even wearing skins and furs.
If you can still find any Chimps and Gorillas in the remaining few square meters of jungle they might be able to teach you how to survive. Or they might just eat you.
Because all the easy to get useful minerals and ores are long since exhausted.
If somehow all the metals that exist in the form of autos, appliances, bridges, transmission towers, soda cans, buildings etc... were to vanish - then that would be a good point.
So I've got this Golden Gate bridge and a pile of automobiles rusting away here. What are we going to use for energy to enable us to do anything with it?
Where you see piles, I see Pyramids, And these Pyramids shall house the benevolent ones that have all the answers.
So, I will be cared for by merely declaring fealty to the reigning Pyramid.. And doing their bidding of course. :blank:
Edit: Oh wait, I'm kind of doing that now, aren't I?? Dang it!!
Because all the easy to get useful minerals and ores are long since exhausted.
But not entirely! Assuming we melt the ice caps on schedule, we'll have an entire continent which has never been exploited at all, suddenly ice-free. As well as all the garbage of our current civilization, of course.
But not entirely! Assuming we melt the ice caps on schedule, we'll have an entire continent which has never been exploited at all, suddenly ice-free. As well as all the garbage of our current civilization, of course.
You mean all the garbage from the lowlands of the coasts like Miami (and much of the South East), Manhattan, New Orleans, Los Angeles, and much of the Bay Area (except San Francisco ironically) will be floating around Antarctica?
Well no Jazzed, Antarctica will all be un-mined ores and oil deposits. Our trash will mostly stay where it is, in the offshore shallows for the most part where it will be a different kind of rich resource.
Greenland is already opening up to mining and mineral exploration. And it is actually more economical than Antarctica on a distance to market. Also there are huge expanses of Siberia, Alaska, and Northern Canada. Meanwhile, the moon is a real looser in terms of distance to market. Austrailia and Brazil seem to continue to provide some of the best iron ore on the planet. Mongolia is opening up to lead the world in copper ore.
What is it we need that can't be gotten on earth?
I do get the idea that it will one day be cheaper to build spaceships either on the moon or in orbit. And at that juncture, mining off planet might be very worthwhile. But for now it takes years to get to Mars. We haven't resolved the radiation shielding or zero-gravity health issues with such a journey. And what would one eat for three years in transit to Mars? (Maybe Kennel-ration?)
Sure we might send someone there and back. But I'd hate to see what was left of him or her. Wait until we can build spaceships with mirco-breweries and provide real dairy for latte machines. Don't forget a good shower and spa.
Comments
She discribes the various types of sword steels used indifferent regions. Regarding Damascus Steel swords. There are two types - one she calls modern damascus and authentic damascus. The basic difference is that modern (including early fake authentic) is made using layers of hard (high carbon) and soft (low carbon) steel bars that are forge welded together, folded, and forged into many very thin layers of hard/soft steel. (I have a couple of knives made with this process and it has some interesting properties.- below)
Authentic damascus steel is made from one piece of "wootz" steel (carbon approx 1.3% to 1.9%, a very high carbon steel.) This steel is very difficult to forge - too hot and it cracks, too cold and it cracks. Forging too slowly in the correct temperature range results in the hard microconstituents (iron carbide) converting to graphite But when heated and forged and heated correctly, it forms fine layers of alternating fine bands of hard and soft components that give the sword its properties. Apparently, some European sword smiths learned how to make such steels in the 16-17 century. However, as swords became less important in warfare, the need for the performance dropped and the very high cost of the process resulted in the process being lost. Forged welded damascus blades had similar appearance (status) and cost less.
There are a number of studies of authentic damascus going on different universities, characterizing the microstructure and trying different methods to reproduce it. And since these are university studies, the intent is to understand the microstructural reactions taking place. There are a few different theories that have some experimental verification. But there is still disagreement as to the methods used historically.
I've used one of my modern damascus knives for wood carving. I've examined the blade on a metallograph at work both after sharpening and after carving wood. When sharpened and stropped, the edge is smooth (and very sharp), since the hard/soft layers are not parallel to the sharpened edge after using the knife to carve wood, the edge is microscopically serrated (and still sharp). Other carving knives I have need to be re-honed after similar amounts of carving.
Tom
Fair cop. My history book missed out some details. I just thought the way they did the heat treatment was very cunning.
The question now is: If at some point we knew how to make something and now we don't, does it matter at all if we understood the underlying processes deeply or not? Call it "lost technology" or "lost craft" who cares? We are still sitting in the dark with no wheels on our wagon and no way to smite our enemies with sharp instruments.
Of course we are curious to find out more about how and why things work. It's amazing though how far we came without knowing anything much.
Some people see the world as a cup half-empty, others see it as a cup half-full.
The idea that we might never get back to the moon due to lost technology is ludicrous. ... an attention-getting device intended to launch loyal patriots into a bunch of NASA jingoisms so that a newpaper can up its circulation.
There is such a term as research, isn't there? We are constantly looking back and revising what we know.
Not just that we cant go to the moon anymore - we even can't produce a decent sword?
Enjoy!
Mike
We can still make plowshares.
@jazzed,
Actually it's much, much worse than that.
Following the collapse of civilization as we know it under the weight of the inevitable third world war, itself brought on by fuel, food and other resource shortages and the ridiculously huge population we have that is busy laying the planet to waste, we won't even be able to aspire to the level of the iron age or the bronze age.
Why?
Because all the easy to get useful minerals and ores are long since exhausted.
Of course we have no animals left so forget about even wearing skins and furs.
If you can still find any Chimps and Gorillas in the remaining few square meters of jungle they might be able to teach you how to survive. Or they might just eat you.
Good luck.
If somehow all the metals that exist in the form of autos, appliances, bridges, transmission towers, soda cans, buildings etc... were to vanish - then that would be a good point.
So I've got this Golden Gate bridge and a pile of automobiles rusting away here. What are we going to use for energy to enable us to do anything with it?
So, I will be cared for by merely declaring fealty to the reigning Pyramid.. And doing their bidding of course. :blank:
Edit: Oh wait, I'm kind of doing that now, aren't I?? Dang it!!
But not entirely! Assuming we melt the ice caps on schedule, we'll have an entire continent which has never been exploited at all, suddenly ice-free. As well as all the garbage of our current civilization, of course.
You mean all the garbage from the lowlands of the coasts like Miami (and much of the South East), Manhattan, New Orleans, Los Angeles, and much of the Bay Area (except San Francisco ironically) will be floating around Antarctica?
What is it we need that can't be gotten on earth?
I do get the idea that it will one day be cheaper to build spaceships either on the moon or in orbit. And at that juncture, mining off planet might be very worthwhile. But for now it takes years to get to Mars. We haven't resolved the radiation shielding or zero-gravity health issues with such a journey. And what would one eat for three years in transit to Mars? (Maybe Kennel-ration?)
Sure we might send someone there and back. But I'd hate to see what was left of him or her. Wait until we can build spaceships with mirco-breweries and provide real dairy for latte machines. Don't forget a good shower and spa.