Exothermic welding is a chemical process which enables the molecular bonding of metals in a long-lasting way. It is applied to metal joints and its use is very widespread in sector such as rail and the electrical sector, in the grounding connections.
Exothermic welding achieves molecular bonding between conductors made of copper, stainless steel, galvanised, bronze, etc. The basis of the process is an exothermic chemical reaction in which the aluminium reduces the copper oxide producing the copper that totally or partially melts the conductors to be welded, providing a superior connection to any mechanical joint (more susceptible to wear and corrosion), with respect to both mechanical and electrical properties.
In this article, we will develop the evolution of exothermic welding since its invention in 1893 to the current innovations, which have meant important improvements in the process.
Thermite Welding Powder
The exothermic welding is based in a termite reaction which was discovered in 1893 by the German chemist Hans Goldschimdt, taking as a starting point the studies of Bekétov. Hence, the aluminothermic is known as the “Goldschmidt reaction”. In 1895. Goldschmidt had developed the process and patented it in Germany.
Years before, between 1859-1865 in the Járkov university (Ukrania) the Ukrainian Nikolai Bekétov started to observe the reaction of aluminium from its oxides which were exposed to high temperatures. These investigations were very relevant since they laid the foundations that led to the subsequent invention of aluminothermic welding.
The first commercial application of the aluminothermic reaction for iron was in 1899 and consisted of welding sections of railway tracks in Essen (Germany). This was exported to the American continent, where its use was extended. Due to the commercial interest, John H. Deppeler patented it in the United States.
As for copper, in 1939, Charles Cadwell made his first non-ferrous application for welding, applying it to electrical connections. In his honor it was called, at first, Cadweld welding. The procedure and format practically did not evolve for years. It has been in this last decade when the most notable innovations have occurred, which have mainly affected the type of loads and ignition, to make the procedure more versatile and safe.
The development and technological innovation of the different manufacturers in the sector have taken the Cadweld process one step further. The Apliweld® system of Aplicaciones Tecnológicas has established itself as the safest and most practical way of the market. For those reasons, day by day more infrastructures around the world use it.
The Exothermic Welding Materials factory from China provides Exothermic Welding Materials for railway welding construction teams, railway contractors, railway procurement departments, and railway supply trading companies. If you are interested in our products, please contact us now!
How to Use Exothermic Welding?
Aug. 26, 2023
