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Thema: Philosophical Transactions on damascus, wootz & other alloys

  1. #1
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    Philosophical Transactions on damascus, wootz & other alloys

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    While doing some internet research on Sheffield made Crucible Steel, i found some interesting reading material in an old English book named Philosophical Transactions, dated 1822.
    Thought you guys might like to read it as well, even though it's in English.

    @ Mods: if this post does not belong here please move it to the appropriate subforum.

    **************************
    Damascus Steel.

    The steel of which the beautiful sword blades of Damascus are manufactured, has hitherto baffled all attempts at imitation.
    It is generally supposed to be made of slips or thin rods or wires of iron and steel, bound together by iron wire, and then melted together by heat.
    The most skilful workmen of other countries have attempted to imitate this process, but in vain; so that there is reason to think that the secret of the manufacture has not yet transpired.
    The colour of the Damascus blades is a dull bluish grey, and scarcely exceeds in hardness common steel from the forge.
    (It is difficult to bend; and when bent does not resume its shape; the principal character, however, is its water, or a peculiar wavy appearance running from the hilt to the point in narrow lines, the thickness of a harpsicord wire, which never cross each other.
    These waving lines arise from a slight difference in the degree of polish occasioned by the unequal action of acid upon the steel; any weak acid would produce this effect, but at Damascus sulphate of alumine is acid.
    This appearance of waving lines has been imitated by a false damasking or etching, but the genuine Damascus blade is distinguished from the false one by the obliteration of the lines in grinding, which takes place in the latter.
    In the real Damascus blades, grinding nearly removes the water; but it immediately reappears by rubbing the blade with lemon juice.

    On Indian Steel or Wootz.

    This valuable material has lately been introduced with great success into cutlery.
    Sir Joseph Banks was the first person who drew the attention of the public to Wootz, having received it from Dr. Scott of Bombay, and submitted some of it to the trials of skilful workmen so early as 1795.
    It is imported in the state of round flat cakes, about five inches in diameter, and an inch thick, each weighing more than two pounds.
    The following is the method of making it in India.
    Pieces of forged iron and wood are enclosed in a crucible, and heated together in a furnace.
    The fire is urged by three or more pair of bellows peculiar to the country.
    In this way the wood is charred, and the iron is melted and converted into steel.
    It crystallizes in the crucible in the state above mentioned.
    According to Mr. Stodart it ought to undergo a second fusion, which should be conducted with the greatest care, and when this is well done, it is so much improved as to be fit for every purpose of fine cutlery, and infinitely superior to the best cast steel of England.
    In forging, it requires the utmost attention.
    Dr. Scott informed Sir Joseph Banks, that it “cannot bear anything beyond a slight red heat;” for when this happens, part of the mass seems to run, and the whole is lost as if it consisted of metals of different degrees of fusibility.
    Mr. Stodart also found that it was useless when overheated, that in hardening it should be quenched at a cherry-red colour, and while tempering, it should be heated from thirty to forty degrees higher than the best English cast steel.
    According to Dr. Pearson’s * analysis, it seems to differ from steel only in containing a little oxide of iron.
    He and Mr. Moore obtained the following measures of its specific gravity.



    Wootz has been more recently (1819) examined by Mr. Faraday.
    The piece which he used was cut from the middle of the cake given by Sir Joseph Banks to Mr. Stodart, when heated cherry-red.
    In 460 grains he found besides the carbon and iron, 0.3 of a grain of silex, and 0.6 of a grain of alumine.
    The best English cast steel, submitted to the same experiments, yielded no earths.
    Mr. Faraday attempted in vain to imitate wootz, although he obtained specimens of iron giving abundance of silex and alumine by analysis.

    On a future occasion, however, he was more successful by employing the following method.
    Pure steel in small pieces, and in some cases good iron when mixed with charcoal powder were heated intensely for a long time.
    In this way were formed carburets highly crystalline, and of a dark metallic grey colour, like the black ore of tellurium.
    When broken the facets of several buttons of 500 grains were about the eighth of an inch wide.
    This carburet consisted of Iron - - - 94.36 Carbon - - 5.64 * 100.00
    This metal when reduced to powder in a mortar was mixed with pure alumine, and the whole subjected to an intense and long heat.
    An alumine alloy was thus obtained of a white colour, a close granular texture, and very brittle.
    It contained 6.4 of alumine: With 67 parts of this alloy 500 grains of good steel were fused, and formed a perfectly malleable button which forged well, and gave the beautiful damask peculiar to wootz, by the application of dilute sulphuric acid.
    This specimen had all the appreciable characters of the best Bombay Wootz.

    Hence Messrs. Stodart and Faraday were of opinion that wootz is steel accidentally combined with the metal of the earths, the earth being either in the ore, or derived from the crucible in which the prism is made.
    It will appear, say these chemists, from the following experiment, that we had formed artificial wootz when it was not the object of research.
    In an attempt to reduce titanium, and combine it with steel, a portion of menachanite was heated with charcoal; a part of the button thus obtained was next fused with some good steel in the proportion of

    Steel - - - - 96 Menachanite button - 4. 100

    The alloy thus obtained worked well under the hammer, and the bar obtained was evidently superior to steel.
    This was ascribed to the presence of titanium, but no titanium could be found in it, not even in the menachanite button itself.
    The product was iron and carbon, combined with the earths or their bases, and was in fact excellent wootz.
    On this specimen a beautiful damask was produced by the action of dilute acid.

    On the Alloys of Steel.

    The curious observation of Sir Humphry Davy, that mercury is rendered solid, and experiences a diminution of specific gravity from 13 to 3 by combining with 12'ondth part of ammonium, seems to have impressed on Mr. Stodart's mind the important fact that a very minute quantity of one metal is capable of producing extraordinary effects by combining with another.
    Hence he was led, in conjunction with Mr. Faraday, to perform a series of interesting experiments on the alloys of steel with small quantities of gold, silver, platinum, rhodium, iridium, osmium, and palladium.”
    A brief account of the results is all that our limits will permit us to give.

    1. Alloy of Steel with Silver.
    When one part of silver and five hundred of steel were properly fused, a button was produced which forged well, and formed various cutting tools decidedly superior to those made of the very best steel.
    The metals were in a state of perfect chemical combination, and by a delicate test the silver could be detected in every part of the alloy.
    When more than sindth part of silver was used, the excess was only mixed mechanically with the steel, and a silvery dew exuded from the metal when it contracted by cold or was hammered.

    2. Alloy of Steel and Platinum.
    An alloy of 100 parts steel and 1 platinum f was forged into bars remarkable for smoothness of surface and beauty of fracture. Though less hard than the preceding alloy, it was considerably tougher.
    This alloy is powerfully acted upon by weak sulphuric acid, the action increasing with the quantity of platinum in the alloy. Equal parts of steel and platinum produced a beautiful alloy, which takes a fine polish, and does not tarnish.
    It is peculiarly suitable for specula, and its specific gravity is 9.862.

    3. Alloy of Steel with Rhodium.
    Alloys of steel with from one to two per cent. of rhodium, possess the valuable property of hardness, with tenacity sufficient to prevent cracking either in forging or hardening.
    This superior hardness is so remarkable, that in tempering for cutting articles, Messrs. Stodart and Faraday found, that they required it to be heated fully 30° Fahrenheit higher than the best wootz, wootz itself requiring to be heated fully 400 above the best English cast steel.
    The great scarcity of rhodium will, however, prevent this alloy from ever getting into general use.

    4. Alloy of Steel with Gold.
    This alloy is good, though it does not promise to be so valuable as the preceding ones.

    5. Triple Alloy of Steel, Iridium, and Osmium.
    This alloy is also one of great value.

    6. Alloy of Steel with Palladium resembles the preceding.

    7. Alloy of Steel with Chromium.
    This alloy was first made by M. Berthier, who speaks very favourably of it.
    Messrs. Stodart and Faraday fused 16oo grains of steel with 10 of pure chrome.
    The button forged well, and though hard showed no disposition to crack.
    Another button, made of 1600 grains of steel and 48 of chrome was harder than the first, but was as malleable as pure iron.

    Tin and copper were also alloyed with steel, but they did not seem to improve it.

    The editor of this work has now before him highly polished specimens of four of these alloys, viz. those of platinum, gold, silver, and rhodium, which were presented to him by the late Mr. Stodart.
    They have now been kept for nearly seven years with different specimens of highly polished steel also given him by Mr. Stodart.
    The specimens of steel are all rusted, while there is not a spot upon any of the alloys.
    The much lamented death of Mr. Stodart has, we fear, delayed for a while the introduction of these valuable alloys into the arts; but we trust the subject will be again resumed by some skilful individual, who unites great practical skill with scientific knowledge.

    * Philosophical Transactions, 1822

    *******************

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  3. #2
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    AW: Philosophical Transactions on damascus, wootz & other alloys

    Very, very funny. Thanks!

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    @AchimW: is there anything in the text above that you think might be interesting or even useful, or is all the information severely outdated and/or utterly useless ?
    And i really value your opinion in this matter.

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    From metallurgical view, the text is between useless and downright false. The interest is in the way the people at that time looked at metallurgy and tried to make better materials by trial and error without fully or even partly understanding the processes involved.

  6. #5
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    Thanks Achim, as all this is not exactly my field of expertise.

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