What happens when voltage is applied in flash welding?

What happens when voltage is applied in flash welding?

• A. A flashing or arcing occurs, which heats the abutting ends to the plastic state due to resistance
• B. The pieces melt completely
• C. The heat is uniform across entire surface
• D. The fixture wears out

Answer: (A)

When voltage is applied in flash welding, a bright arc (flash) forms across the gap between the ends. This arc, together with the intense current through the small contact area, causes rapid resistance heating right at the abutting ends. The temperature rises very quickly, softening the ends to a plastic state so they can be pressed together to form a strong weld. The process relies on localized heating rather than melting the entire pieces, and the arc also helps break up surface oxides to improve bonding. The fixture’s wear might occur over time, but that isn’t what the welding action relies on.

When voltage is applied in flash welding, a bright arc (flash) forms across the gap between the ends. This arc, together with the intense current through the small contact area, causes rapid resistance heating right at the abutting ends. The temperature rises very quickly, softening the ends to a plastic state so they can be pressed together to form a strong weld. The process relies on localized heating rather than melting the entire pieces, and the arc also helps break up surface oxides to improve bonding. The fixture’s wear might occur over time, but that isn’t what the welding action relies on.