Langmuir torch

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The Langmuir torch (also known as Arcatom welding) is a welding process that was developed by Irving Langmuir in 1924.

The welding process splits hydrogen molecules in an electric arc , through which hydrogen gas flows, between two tungsten electrodes into atomic hydrogen . The gas from atomic hydrogen is directed onto the metal surface to be welded and reunites to form hydrogen molecules. The heat of reaction released during this process can reach temperatures of up to 4000 ° C for welding. In addition, the hydrogen serves as a protective gas , which prevents oxidation . Only a few compounds, such as tantalum hafnium carbide or substoichiometric tantalum carbide, cannot be melted with it.

Differences to other welding processes

While arc welding creates an arc between a metallically conductive material and the electrode, it is possible to melt nonconductive materials with the Langmuir torch by transferring the supplied heat to the workpiece via the hydrogen heated in the arc between two tungsten electrodes and on the other hand, the recombination heat of atomic hydrogen increases it to molecular level. This is where the main difference to the arc welding process can be seen, which distinguishes between melting (material feed) and non-melting (mostly tungsten electrodes) electrodes, see welding and tungsten inert gas welding . These mostly use noble gases that do not react with the materials, i.e. they remain inert.

Video documentation

Individual evidence

  1. Patent US1947267A : Heating process and apparatus. Registered July 30, 1924 , published February 13, 1934 , inventor: Langmuir Irving.
  2. Irving Langmuir, GMJ Mackay: THE DISSOCIATION OF HYDROGEN INTO ATOMS. Part I. Experimental . In: Journal of the American Chemical Society . tape 36 , no. 8 , August 1, 1914, p. 1708–1722 , doi : 10.1021 / ja02185a011 .