What method is used in exothermic welding?

The method used in exothermic welding is known as Cad weld or exothermic welding. This process involves a chemical reaction that generates intense heat, allowing two conductive materials, often metals like copper, to bond together. The reaction typically involves powdered materials such as aluminum and copper oxide, which, when ignited, produce molten metal that fuses the materials without the need for external electrical or gas sources.

This method is favored in various applications due to its ability to create a strong, durable connection and its effectiveness in environments where traditional welding techniques might be impractical. It is widely used in the electrical industry for making connections between cables, grounding connections, and other scenarios where a reliable metallic bond is critical.

The other options, like arc welding, cryogenic welding, and gas welding, do not align with the exothermic process as they involve different principles and methods of creating heat and joining materials. For instance, arc welding relies on an electric arc to melt the base metals, while gas welding uses a flame produced by burning gases. These methods do not utilize the exothermic reaction that characterizes Cad welding.