Induction welding
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Induction welding is a form of welding that uses electromagnetic induction to heat the workpiece. The welding apparatus contains an induction coil that is energised with a radio-frequency electric current. This generates a high-frequency electromagnetic field that acts on either an electrically conductive or a ferromagnetic workpiece. In an electrically conductive workpiece, such as steel, the main heating effect is resistive heating, which is due to magnetically induced currents called eddy currents. In a ferromagnetic workpiece, such as plastic doped with ceramic particles, the heating is caused mainly by hysteresis as the magnetic component of the electromagnetic field repeatedly distorts the crystalline structure of the ferromagnetic material. In practice, most materials undergo a combination of these two effects.
As suggested above, nonmagnetic materials such as plastics can be induction-welded by implanting them with metallic or ferromagnetic compounds, called susceptors, that absorb the electromagnetic energy from the induction coil, become hot, and lose their heat energy to the surrounding material by thermal conduction.Template:Industry-stub