What Does Exothermic Welding Mean?
Exothermic welding is a fusion welding process. Unlike many other welding processes, the source of energy does not come from electricity, combustion or mechanical means. Instead, the energy is obtained from a chemical reaction. The heat from this chemical reaction coalesces two or more materials together.
Exothermic welding creates the heat necessary for welding using the chemical reaction that occurs when aluminum powder is combined with a metal oxide. The two or more materials that are to be combined are placed together with a special crucible. The combination of aluminum powder and metal oxide is then ignited. This sets off the chemical reaction. The heat from this chemical reaction melts the powders. The molten metal flows down the crucible and melts the materials to be welded. Once the chemical reaction is finished, the metal solidifies. The crucible is removed and the slag and excess metal is cleaned up. This is typically done by a grinding process.
Exothermic welding is also known as thermite welding.