A brazing process using an exothermic chemical reaction between a metal oxide and a metal or inorganic nonmetal as the heat source, with filler metal preplaced in the joint.
In this process, a commercial filler metal is heated by a solid-state exothermic chemical reaction, which releases heat as the free energy of the reactants. Exothermic brazing uses simplified tooling and equipment. The reaction heat brings adjoining metal
interfaces to a temperature at which preplaced brazing filler metal melts and wets the base metal interface surfaces. Several commercially available brazing filler metals have suitable flow temperatures. The process is limited only by the thickness of the base metal and the effect of brazing heat, or any previous heat treatment, on the metal properties.
Reference: American Welding Society. Welding Handbook, Vol. 2, 8th Edition. Miami, Florida: American Welding Society, 1991.