Kuyabribri (talk | contribs) capitalized CADWELD throughout remainder of article, added context to lede |
ERICOLEGAL (talk | contribs) Reverted to appropriate language per ERICO's CADWELD® trademark and CADWELD® patented process. Added CADWELD® Process image. |
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:'''CADWELD<sup>®</sup>''' is a brand of welded electrical connections. For the generic item, see [[exothermic welding]].'' |
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In 1938, Dr. Charles Cadwell, of the Electric Railway Improvement Company (ERICO), invented a copper-based alumino-thermic (exothermic) welding process for welding copper conductors to steel rails. It was immediately trade named CADWELD<sup>®</sup> by ERICO, now called [http://www.erico.com ERICO International Corporation]. The CADWELD<sup>®</sup> process is a method of making electrical connections of copper-to-copper or copper-to-steel in which no outside source of heat or power is required. |
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In [[metalworking]], a '''CADWELD''' is the joining together of two [[Heat conductor|conductors]] of like or dissimilar materials by [[exothermic reaction]]. |
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It is a chemical reaction of granular metals (granular copper oxide and aluminium) which produces molten metal. This reaction, which is completed in seconds, takes place in a graphite crucible. The reduction of the copper oxide by the aluminium (exothermic reaction) produces molten copper and aluminium oxide slag. The slag floats to the surface and the liquid copper flows from this crucible section into a mold section where it joins the ends of the conductors to be welded. The temperature of the metal is sufficient to fuse the metal ends of the conductors and results in a molecular bond. The weld is allowed to solidify. The mold is then removed and made ready for the next weld. The entire process takes seconds to complete. |
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The process uses a mixture of several chemicals. A mixture of copper oxides ([[copper(II) oxide]] and [[copper(I) oxide]]) and [[aluminium]] powder provide the main exothermic mixture: |
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A CADWELD<sup>®</sup> exothermic welded connection produces a joint (or connection) superior in performance to any known mechanical or pressure type surface-to-surface contact electrical connector. By virtue of its molecular bond, a CADWELD<sup>®</sup> welded connection will not loosen or increase in resistance over the lifetime of the installation and provides current carrying capacity equal to or greater than that of the conductors. |
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: 3CuO + 2Al = 3Cu + Al<sub>2</sub>O<sub>3</sub> + Heat. |
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[[File:CADWELD_Process_w.jpg\thumb\CADWELD<sup>®</sup> Process]] |
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The formula also contains [[tin]] metal or [[Tin(IV) oxide|its oxide]] and [[calcium fluoride]]. Some formulations also contain [[calcium silicide]] and have the aluminium present as an alloy with copper and [[vanadium]]<ref>''CADWELD Electrical Welding Material;'' MSDS No. LT1273; ERICO: Solon, Ohio, March 1, 2007. [http://www.erico.com/public/library/MSDS/LT1273.pdf]</ref><ref>''CADWELD Aluminum Welding Material;'' MSDS No. LT1272; ERICO: Solon, Ohio, March 1, 2007. [http://www.erico.com/public/library/MSDS/LT1272.pdf]</ref>. |
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CADWELD<sup>®</sup> and ERICO<sup>®</sup> are registered trademarks of ERICO International Corporation, Solon, Ohio, USA. The company continues to produce a line of CADWELD<sup>®</sup> products out of its Solon headquarters. |
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The CADWELD process was invented in [[Cleveland]] by Charles A. Cadwell in 1938, while he was working for the Electric Railway Improvement Company, now called ERICO. The name "CADWELD" is still a registered trademark of ERICO, which produces a line of CADWELD products out of its headquarters in [[Solon, Ohio]]. |
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== See also == |
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* [[Thermite]] |
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http://www.erico.com |
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{{reflist}} |
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[[Category:History of Cleveland, Ohio]] |
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{{metalworking-stub}} |
Revision as of 16:01, 16 April 2009
- CADWELD® is a brand of welded electrical connections. For the generic item, see exothermic welding.
In 1938, Dr. Charles Cadwell, of the Electric Railway Improvement Company (ERICO), invented a copper-based alumino-thermic (exothermic) welding process for welding copper conductors to steel rails. It was immediately trade named CADWELD® by ERICO, now called ERICO International Corporation. The CADWELD® process is a method of making electrical connections of copper-to-copper or copper-to-steel in which no outside source of heat or power is required.
It is a chemical reaction of granular metals (granular copper oxide and aluminium) which produces molten metal. This reaction, which is completed in seconds, takes place in a graphite crucible. The reduction of the copper oxide by the aluminium (exothermic reaction) produces molten copper and aluminium oxide slag. The slag floats to the surface and the liquid copper flows from this crucible section into a mold section where it joins the ends of the conductors to be welded. The temperature of the metal is sufficient to fuse the metal ends of the conductors and results in a molecular bond. The weld is allowed to solidify. The mold is then removed and made ready for the next weld. The entire process takes seconds to complete.
A CADWELD® exothermic welded connection produces a joint (or connection) superior in performance to any known mechanical or pressure type surface-to-surface contact electrical connector. By virtue of its molecular bond, a CADWELD® welded connection will not loosen or increase in resistance over the lifetime of the installation and provides current carrying capacity equal to or greater than that of the conductors.
[[File:CADWELD_Process_w.jpg\thumb\CADWELD® Process]]
CADWELD® and ERICO® are registered trademarks of ERICO International Corporation, Solon, Ohio, USA. The company continues to produce a line of CADWELD® products out of its Solon headquarters.
References