Also found in: Dictionary, Thesaurus, Acronyms, Wikipedia.
flash welding[′flash ‚weld·iŋ]
A form of resistance welding that is used for mass production. The welding circuit consists of a low-voltage, high-current energy source (usually a welding transformer) and two clamping electrodes, one stationary and one movable.
The two pieces of metal to be welded are clamped tightly in the electrodes, and one is moved toward the other until they meet, making light contact. Energizing the transformer causes a high-density current to flow through small areas that are in contact with each other. Flashing starts, and the movable workpiece must accelerate at the proper rate to maintain an increasing flashing action. After a proper heat gradient has been established on the two edges to be welded, an upset force is suddenly applied to complete the weld. This upset force extrudes slag, oxides, molten metal, and some of the softer plastic metal, making a weld in the colder zone of the heated metal. See Resistance welding