Another wootz question

[Jeff D]

Originally Posted by ariel

If that's the case, the difference between Persian, Indian and even Turkish wootz blades might have been mostly, if not exclusively, due to technical aspects of handling ingots. Temperature, duration of forging, force of pounding, orientation of the ingot, altered directions of forging, speed of cooling etc. were responsible for different patterns.
With tens of thousands of wootz ingots coming from India on an yearly basis, the smith needed just to verify that a particular ingot was indeed " wootzy", did not have a lot of slag trapped inside and ... that's it. From there on, the ultimate result depended strictly on the master's skills.
This, likely, explains why the contemporary masters have such hard time to reproduce the beauty of old Indian and Persian blades. Contemporary metallurgy knows precisely the nature of wootz, the percentage of carbon and the microelements facilitating formation of dendrites, the temperature/time optimization of the process etc. This is purely science, and we are very good at it.
What is missing, is the hands-on collection of idiosyncratic manipulations peculiar to old artists: how hard to pound, at what metal color, when to turn, when to grind and how much , how to cool etc, etc, etc.

Here is an example of a bulat (wootz) dagger by Anosov
http://talks.guns.ru/forums/icons/fo...81/1681918.jpg
http://talks.guns.ru/forums/icons/fo...81/1681922.jpg
http://talks.guns.ru/forums/icons/fo...81/1681920.jpg
He got the secret.

I don't think this is true. The Ingot was also critical. Kindi even stated it;
'Swords made in Yemeni workshops from Yemeni crucible steel were regarded as the highest quality swords, whereas those made by Yemeni swordsmiths using imported crucible steel were classified only as medium quality. This classification was absolute; the best Yemeni sword-smith could only achieve a medium quality blade even if the best quality imported Indian crucible steel was used.' Pg 59, Hoyland and Gilmore
Medieval Islamic swords and Swordmaking

Jeff

[ariel]

Are there any surviving examples of Yemeni wootz swords? Tough to judge with only hearsay for evidence...

[Jeff D]

Originally Posted by ariel

Tough to judge with only hearsay for evidence...

True, but hearsay is a higher power then speculation.

More hearsay; ' Biruni may have been getting his information from another source as well for he goes on to say (in so many words) that, while he is willing to believe that a sword of one type could not be changed into another, the ingredients of the steel could be changed (in the crucible) so as to produce different watered effects, revealed by final polishing.' Pg 173 of Hoyland and Gilmore.

Jeff

[Gonzalo G]

Jeff, how important could it be the presence on enough manganese in the crucible to produce different banded effects, as it seems to have incidence over the carbon segregation? Could it be a factor to explain some of this differences?
Regards

Gonzalo

[Jeff D]

Originally Posted by Gonzalo G

Jeff, how important could it be the presence on enough manganese in the crucible to produce different banded effects, as it seems to have incidence over the carbon segregation? Could it be a factor to explain some of this differences?
Regards

Gonzalo

Hi Gonzalo,

I am not a metallurgist, But, I thought the Manganese dioxide was added to neutralize the Sulfur in the iron, which makes the blade too brittle to work with when heated. Verhoeven does state that very small traces of Manganese will promote banding (less effect then Vanadium). I think trace amounts are usually present anyway, so I don't think that is the reason it was added to the crucible.
I personally feel that it is more likely the original source of the iron, with its inherent properties that made the biggest difference. The other ingredients and etchants may have helped or hindered somewhat but Like Verhoven did, a smith would keep hitting a wall until the right iron was found. I agree with ariel that a poor smith even with the correct iron could loose the effect.

All the Best
Jeff

[Gonzalo G]

I agree, Jeff. But manganese also has been mentioned by some metallurgists as an ingredient affecting the dendritic structure and appearance of the wootz, and not only as a mean to neutralize the sulphur. Nevermind, I was only trying to check this point. With respect to the vanadium, the same can be said. I understand indian ores were characterized by the presence of vanadium. I don´t know if somebody had conducted experiments in this way, changing the additional ingredients, or their amount, and using the same forging technique, to see the possible changes on the appearance of the dendritic structure. Of course, forging techniques had great inicidence to this respect, but I was only intending to see the differences originated on the making of the ingots. Thank you.
Regards

Gonzalo

[Jeff D]

Hi Gonzalo,

Vanadium, Molybdenum, chromium, niobium and manganese all produce the effect. The elements can be found naturally in different quantities in different ores depending on their source. These are the one mentioned by Verhoeven in his 2001 Scientific America article. I am sure there are others as well. I suppose these elements could have been added to the crucible, but, I am sure the ingredients would be a highly guarded secret. I suspect the additions were not entirely known or the smiths imported into Spain would have been able to reproduce the watered pattern from the local ores. Apparently they were not.

All the Best
Jeff