Which welding process uses a chemical reaction to fuse metals without melting the base metals?

Which welding process uses a chemical reaction to fuse metals without melting the base metals?

• A. TIG welding
• B. Arc welding
• C. Exothermic welding
• D. MIG welding

Answer: (C)

Exothermic welding uses a chemical reaction to fuse metals without melting the base metals. A thermite-like mixture reacts to produce molten metal that flows into a mold and bonds with the surrounding conductors as it cools. The heat comes from the chemical reaction itself, not from melting the base metals with an external heat source, so the parent pieces remain largely unmelted. In contrast, TIG, arc, and MIG welding rely on an external heat source to melt the metals (and often a filler) to form the joint. Exothermic welding therefore achieves a strong, conductive bond without melting the base metals.

Exothermic welding uses a chemical reaction to fuse metals without melting the base metals. A thermite-like mixture reacts to produce molten metal that flows into a mold and bonds with the surrounding conductors as it cools. The heat comes from the chemical reaction itself, not from melting the base metals with an external heat source, so the parent pieces remain largely unmelted. In contrast, TIG, arc, and MIG welding rely on an external heat source to melt the metals (and often a filler) to form the joint. Exothermic welding therefore achieves a strong, conductive bond without melting the base metals.