Editing Pattern welding

{{short description|Swordmaking technique}}
[[File:Pattern Welded Sword Blade by Ejvind Nørgård.jpg|thumb|414x414px|A contemporary pattern-welded sword blade made by Danish swordsmith Ejvind Nørgård. The blade shows a chevron pattern with opposing twists and straight laminate alternating.]]
'''Pattern welding''' is a practice in [[sword]] and [[knife]] making by forming a blade of several [[metal]] pieces of differing composition that are [[forge welding|forge-welded]] together and twisted and manipulated to form a pattern.{{sfn|Birch|2013|pages=127–134}} Often called [[Damascus steel]], blades [[forge]]d in this manner often display bands of slightly different patterning along their entire length. These bands can be highlighted for cosmetic purposes by proper polishing or [[acid]] [[industrial etching|etching]]. Pattern welding was an outgrowth of [[laminated steel blade|laminated or piled steel]], a similar technique used to combine steels of different [[carbon]] contents, providing a desired mix of hardness and toughness.  Although modern [[steelmaking]] processes negate the need to blend different steels,{{sfn|Verhoeven|2002|page=357}} pattern welded steel is still used by custom knifemakers for the cosmetic effects it produces.

==History==
[[File:Knife blade 600dpi spine 1200dpi.jpg|thumb|right|An image of a modern pattern welded knife blade, showing the dramatic patterning on the side below, and the layering of the steel in the spine above.  [[Acid]] [[etching]] darkens the 1080 plain [[carbon steel]] more than it does the 15N20 [[alloy steel|low alloy]] [[nickel]] steel, producing alternating bands of light and dark on the surface.]]
Pattern welding developed out of the necessarily complex process of making blades that were both [[hardness|hard]] and [[toughness|tough]] from the erratic and unsuitable output from early iron smelting in [[bloomery|bloomeries]].  The bloomery does not generate temperatures high enough to melt iron and steel, but instead [[redox|reduces]] the [[iron oxide]] [[ore]] into particles of pure [[iron]], which then weld into a mass of [[sponge iron]], consisting of lumps of impurities in a matrix of relatively pure iron, which is too soft to make a good blade.  [[Carburizing]] thin iron bars or plates forms a layer of harder, high carbon steel on the surface, and early bladesmiths would forge these bars or plates together to form relatively homogeneous bars of steel.  This laminating process, in which different types of steel together produce patterns that can be seen in the surface of the finished blade, forms the basis for pattern welding.{{sfn|Verhoeven|2002|pages=356-365}}{{sfn|Peirce|Oakeshott|2004}}

===Pattern welding in Europe===
Pattern welding dates to the first millennium BC, with Celtic, and later Germanic swords exhibiting the technique,<ref>{{Cite journal|last=Maryon|first=Herbert|date=1960|title=Pattern-Welding and Damascening of Sword-Blades: Part 1 Pattern-Welding|url=http://www.jstor.org/stable/1505063|journal=Studies in Conservation|volume=5|issue=1|pages=25–37|doi=10.2307/1505063|jstor=1505063 |issn=0039-3630|url-access=subscription}}</ref> with the Romans describing the blade patternation.<ref>{{Cite web|last=Randolph|first=Octavia|title=Pattern Welded Swords|url=https://octavia.net/pattern-welded-swords/|access-date=2020-07-30|website=octavia.net}}</ref>{{sfn|Williams|2012|page=[https://books.google.com/books?id=FW5FaeZEVAsC&pg=PA75 75]}}
<!-- The earliest known use of pattern welding in Europe is from an 8th century [[BCE]] sword found at Singen, Württemberg in Germany.{{sfn|Peirce|Oakeshott|2004}}<ref>Salter & Ehrenreich, 1984</ref> -->By the 2nd and 3rd century AD, the [[Celts]] commonly used pattern welding for decoration in addition to structural reasons. The technique involves folding and forging alternating layers of steel into rods, then twisting the steel to form complex patterns when forged into a blade.{{sfn|Verhoeven|2002|pages=356-365}}  By the 6th and 7th centuries, pattern welding had reached a level where thin layers of patterned steel were being overlaid onto a soft iron core, making the [[sword]]s far better as the iron gave them a flexible and springy core that would take any shock from sword blows to stop the blade bending or snapping. By the end of the [[Viking Age]], pattern welding fell out of use in Europe.{{sfn|Peirce|Oakeshott|2004}}{{sfn|Peirce|Oakeshott|2004}}{{sfn|Peirce|Oakeshott|Jones|2007|page=[https://books.google.com/books?id=4-J3uhtPZ8MC&pg=PA145 145]}}

In medieval swords, pattern welding was more prevalent than commonly thought.  However, the presence of rust makes detection difficult without repolishing.{{sfn|Williams|2012|page=[https://books.google.com/books?id=FW5FaeZEVAsC&pg=PA75 75]}}

During the [[Middle Ages]], [[Wootz steel]] was produced in [[India]] and exported globally, including to Europe.  The similarities in the markings led many to believe it was the same process being used, and pattern welding was revived by European smiths who were attempting to duplicate the [[Damascus steel]].  While the methods used by Damascus smiths to produce their blades was lost over the centuries, recent efforts by metallurgists and bladesmiths (such as Verhoeven and Pendray) to reproduce steel with identical characteristics have yielded a process that does not involve pattern welding.{{sfn|Verhoeven|2002|pages=356-365}}
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The technique is more commonly associated with [[Japan]] and reached a high degree of development in the fourteenth century.   This association leads some to incorrectly believe that pattern welding originated in Japan.  There are also examples of pattern welding in weaponry from the pre-colonial [[Philippines]] and Indonesia.
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The ancient swordmakers exploited the [[aesthetic]] qualities of pattern welded steel. The [[Viking]]s,<ref>{{Cite web|date=2020-07-08|title=Ancient blacksmiths were pioneers of modern welding|url=https://weldingvalue.com/2020/07/ancient-blacksmiths-were-pioneers-modern-welding/|access-date=2021-12-19|website=Welding Value|language=en-US}}</ref> in particular, were fond of twisting  bars of steel around each other, welding the bars together by hammering and then repeating the process with the resulting bars, to create complex patterns in the final steel bar. Two bars twisted in opposite directions created the common [[chevron (insigne)|chevron]] pattern. Often, the center of the blade was a core of soft steel, and the edges were solid high carbon steel, similar to the laminates of the Japanese.<ref>{{Cite book |last=Tylecote |first=Ronald F. |title=The metallography of early ferrous edge tools and edged weapons |last2=Gilmour |first2=Brian J. J. |last3=Tylecote |first3=R. F. |last4=Gilmour |first4=B. J. J. |date=1986 |publisher=British Archaeological Reports |isbn=978-0-86054-401-2 |series=British archaeological reports British series |location=Oxford}}</ref>

===Modern decorative use===
Pattern welding is still popular with contemporary bladesmiths both for visual effect and for recreating historic patterns and swords.<ref>{{Cite web |date=2023-01-19 |title=Pattern Welding Explained |url=https://www.provos.org/p/pattern-welding-explained/ |access-date=2023-05-19 |website=Niels Provos |language=en-us}}</ref> Modern steels and methods allow for patterns with much higher number of visible layers compared to historical artifacts. Large numbers of layers can either be produced by folding similar to historical processes or by forge welding a small number of layers together, then cutting the billet in pieces to stack and forge-weld it again. This can be repeated until the desired number of layers have been achieved. A blade ground from such a blank can show a pattern similar to wood grain with small random variations in pattern.  Some manufactured objects can be re-purposed into pattern welded blanks.  "Cable Damascus", forged from high carbon multi-strand cable, is a popular item for bladesmiths to produce, producing a finely grained, twisted pattern, while [[chainsaw]] chains produce a pattern of randomly positioned blobs of color.{{sfn|Goddard|2000| pages=107–120}}<ref name=caffery1>{{cite web |url=http://www.caffreyknives.net/damas.htm |title=Damascus Pictorial |first1=Ed |last1=Caffery |url-status=dead |archive-url=https://web.archive.org/web/20110723034406/http://www.caffreyknives.net/damas.htm |archive-date=2011-07-23 }}</ref><ref name=caffery2>{{cite web |url=http://www.caffreyknives.net/bsteel.htm |title=Bits of Steel |first1=Ed |last1=Caffery |url-status=dead |archive-url=https://web.archive.org/web/20051215152635/http://www.caffreyknives.net/bsteel.htm |archive-date=2005-12-15 |via=[[Internet archive]]}}</ref>

Some modern bladesmiths have taken pattern welding to new heights, with elaborate applications of traditional pattern welding techniques, as well as with new technology.  A layered billet of steel rods with the blade blank cut perpendicular to the layers can also produce some spectacular patterns, including [[mosaic]]s or even writing. [[Powder metallurgy]] allows alloys that would not normally be compatible to be combined into solid bars.  Different treatments of the steel after it is ground and polished, such as [[bluing (steel)|bluing]], etching, or various other chemical surface treatments that react differently to the different metals used can create bright, high-contrast finishes on the steel. Some master smiths go as far as to use techniques such as [[electrical discharge machining]] to cut interlocking patterns out of different steels, fit them together, then weld the resulting assembly into a solid block of steel.<ref name=caffery2 />

Blacksmiths will sometimes apply [[Wite-Out]], [[Liquid Paper]], or other types of correction fluid to metal that they do not want to weld together, as the [[titanium dioxide]] in the correction fluid forms a barrier between the metal it is applied-to and any other pieces of metal. For example, when creating pattern-welded steel by filling a steel canister with pieces of metal and powdered steel and forging it together into a single mass ("[https://en.wiktionary.org/wiki/canister%20damascus canister damascus steel],") smiths frequently coat the inside of the canister with correction fluid and let it dry before adding their materials. Thus, when the canister is [[forge welding|heated and compressed using a hammer or pneumatic press]], the material on the inside of the correction fluid is forged together, but it does not forge to the canister, allowing the pattern created by forging the different materials together to be seen in the finished piece because it is not covered by the homologous steel of the canister. {{Citation Needed|date=October 2023}}

==Etymology==
The term 'pattern welding' was coined by English archaeologist [[Herbert Maryon]] in a 1948 paper: "The welding of these swords represents an excessively difficult operation. I do not know of finer smith's work... I have named the technique ‘pattern welding’... Examples of pattern-welding range in date from the third century to the Viking Age."<ref>Maryon, Herbert (1948). "A Sword of the Nydam Type from Ely Fields Farm, near Ely". Proceedings of the Cambridge Antiquarian Society. XLI: 73–76. doi:10.5284/1034398</ref><ref>Bruce-Mitford, Rupert (1949). "The Sutton Hoo Ship-Burial: Recent Theories and Some Comments on General Interpretation" (PDF). Proceedings of the Suffolk Institute of Archaeology. Ipswich. XXV (1): p. 67 n. 269</ref><ref>Maryon, Herbert (February 1960). "Pattern-Welding and Damascening of Sword-Blades—Part 1: Pattern-Welding". Studies in Conservation. 5 (1): p. 26. JSTOR 1505063</ref>

==See also==
* [[Bulat steel]], a [[Russia]]n crucible steel
* [[Damascus steel]], a steel used in swordmaking during the [[medieval period]]
* ''[[Forged in Fire (TV series)|Forged in Fire]]'' a [[History channel]] competitive television show on forged knife and sword making
* [[Hamon (swordsmithing)]]
* [[Japanese sword construction]] includes a specific form of pattern welding.
* [[Mokume-gane]], a similar technique, often for precious metals, used to produce decorative pieces
* [[Wootz steel]], an [[India]]n [[crucible steel]]

==References==
{{reflist}}

==Sources==
* {{cite book | last = Birch | first = Thomas | editor1-last = Dungworth | editor1-first = David | editor2-last = Doonan | editor2-first = Roger C. P. | title = Accidental and Experimental Archaeometallurgy | series = HMS Occasional Publications | volume = 7 | date = 2013 | publisher = [[Historical Metallurgy Society|The Historical Metallurgy Society]] | location = London |pages=127–134 | chapter = Does pattern-welding make Anglo-Saxon swords stronger? | chapter-url = https://www.researchgate.net/publication/274067812 | isbn = 978-0-9560225-1-6 | name-list-style = amp }} {{free access}}
* {{cite book |title=Damascus and pattern-welded steels - Forging blades since the iron age: Forging blades since the iron age: Science des matériaux |first1=Madeleine |last1=Durand-Charre |year=2014 |location=Les Ulis, France|edition=Reprint |publisher=[[EDP Sciences]] |isbn=978-2759816354 }}
* {{cite book | last1 = Engstrom | first1 = Robert | last2 = Lankton | first2 = Scott Michael | last3 = Lesher-Engstrom | first3 = Audrey | title = A Modern Replication Based on the Pattern-Welded Sword of Sutton Hoo | date = 1989 | publisher = Medieval Institute Publications, [[Western Michigan University]] | location = Kalamazoo, Michigan | isbn = 0-918720-29-X | name-list-style = amp }}
* {{cite book | last = Goddard| first = Wayne| title =The Wonder of Knifemaking |location=Iola, Wisconsin|publisher =[[Krause Publications]]| year = 2000| pages =107–120 | isbn = 978-0-87341-798-3}}
* {{cite book |date=May 1, 1994 |title=The Pattern-Welded Blade: Artistry In Iron |first1=Jim |last1=Hrisoulas |edition=Illustrated |publisher=[[Paladin Press]] |isbn=9781581605440}}
* {{cite book |title=The Rise and Fall of Pattern Welding: An Investigation Into the Construction of Pre-medieval Sword Blades |first1=Janet |last1=Lang |publisher=[[University of Reading]]. School of Human and Environmental Sciences }}
* {{cite journal | last = Maryon | first = Herbert | author-link = Herbert Maryon | date = 1948 | title = A Sword of the Nydam Type from Ely Fields Farm, near Ely | journal = Proceedings of the Cambridge Antiquarian Society |publisher=[[Cambridge Antiquarian Society]] | volume = XLI | pages = 73–76 | doi = 10.5284/1034398 }}
* {{cite journal | last = Maryon | first = Herbert | author-link = Herbert Maryon | date = February 1960 | title = Pattern-Welding and Damascening of Sword-Blades—Part 1: Pattern-Welding|journal = Studies in Conservation | volume = 5 | issue = 1 |publisher=[[Taylor & Francis, Ltd.]] on behalf of the [[International Institute for Conservation of Historic and Artistic Works]]|pages=25–37 | doi = 10.2307/1505063 | jstor = 1505063 }}
* {{cite journal | last = Maryon | first = Herbert | author-link = Herbert Maryon | date = May 1960 | title = Pattern-Welding and Damascening of Sword-Blades—Part 2: The Damascene Process | journal = Studies in Conservation |publisher=Taylor & Francis, Ltd. on behalf of the International Institute for Conservation of Historic and Artistic Works| volume = 5 | issue = 2 | pages = 52–60 | doi = 10.2307/1504953 | jstor = 1504953 }}
* {{cite book | last = Meilach | first = Dona Z. | title = Decorative and Sculptural Ironwork: Tools, Techniques, Inspiration | edition = 1st | date = 1977 | publisher =[[Crown Publishers, Inc.]] | location = New York City | isbn = 0-517-52731-6 }}
* {{cite book | last = Meilach | first = Dona Z. | title = Decorative and Sculptural Ironwork: Tools, Techniques & Inspiration | edition = 2nd | date = 1999 | publisher =[[Schiffer Publishing]] | location = Atglen, Pennsylvania | isbn = 0764307908 }}
* {{cite book |chapter-url= https://books.google.com/books?id=4-J3uhtPZ8MC&pg=PA145 |page=145 |first3=Lee A. |last3=Jones |chapter=Blade Construction and Pattern-Welding |isbn=9781843830894 |publisher=[[Boydell & Brewer|Boydell & Brewer, Limited]] |date=May 24, 2007 |edition=New |title=Swords of the Viking Age: catalogue of examples |location=Woodbridge, UK, Rochester, NY|first1=Ian |last1=Peirce |first2=Ewart |last2=Oakeshott }}
* {{cite book  | last1 = Peirce | first1 = Ian G. | last2 = Oakeshott | first2 = Ewart | author2-link = Ewart Oakeshott | title = Swords of the Viking Age | date = 2004 | publisher =[[Boydell & Brewer|Boydell Press]] | location = Woodbridge | isbn = 0-85115-914-1 | name-list-style = amp }}
* {{cite journal |title=Genuine Damascus Steel: a type of banded microstructure in hypereutectoid steels |journal=Materials Technology |url=http://www.mse.iastate.edu/fileadmin/www.mse.iastate.edu/static/files/verhoeven/steelresearchsize2.pdf |archive-url=https://web.archive.org/web/20060903054157/http://www.mse.iastate.edu/fileadmin/www.mse.iastate.edu/static/files/verhoeven/steelresearchsize2.pdf |archive-date=3 September 2006 |first1=John D. |last1=Verhoeven |volume=Steel Research, 73 |number=8 |publisher=[[Iowa State University]] |pages=356–365  |year=2002|via=Internet Archive}}
* {{cite book |url=https://books.google.com/books?id=FW5FaeZEVAsC&pg=PA75 |title=The Sword and the Crucible: A History of the Metallurgy of European Swords Up to the 16th Century |series=History of Warfare (Book 77)|first1=Alan |last1=Williams |type=Hardcover |location=Leiden|publisher=[[Brill Publishers]] |date=May 3, 2012 |isbn=978-9004227835 |page=75 }}

==External links==
* [https://www.provos.org/p/pattern-welding-explained/ Pattern Welding Explained]
* [https://web.archive.org/web/20060219161252/http://www.staff.hum.ku.dk/dbwagner/REHD/REHD.html Ancient carburisation of iron to steel: a comment]
* [http://www.vikingsword.com/virtmus.html Mediæval Sword Virtual Museum], which contains close-up images of Viking swords, showing the pattern welding structures.

[[Category:Welding]]
[[Category:Steelmaking]]
[[Category:Edged and bladed weapons]]