Supplying some materia continuously with energy leads to a rise in temperature, and turns it into a liquid and then into a gaseous state. By adding more energy the energy of motion of the elementary components rises with the temperature up to a point where the atomic shell, consisting of electrones is cracked by the collision of the gas molecules and the atoms thus creating negative electrones and positive ions. This mixture of neutral, positive and negative particles is called plasma, which possesses an electrical conductivity because of its high temperature.
The so-called 4th state of matter plasmas show unusual new characteristics because of the overlay of numerous different effects of nuclear physics. Plasmas are easily to influence by surrounding electric and magnetic fields thus being perfectly navigatable. Due to their high impact of energy, they enable processes that cannot be done with other states of materia. These characterics make plasma a highly performing and flexible tool for many industrial applications.
Inside a plasma torch, there is first a DC voltage between the negative electrode and the nozzle as well as between the electrode and the electrically conductive workpiece. High voltage impulses parallel to the DC voltage between electrode and nozzle create a plasma jet of low energy inside the torch i.e. the so-called pilot arc. The plasma gas becomes dissociated (molecules become atoms) and ionized (electrones leave their shell), then it leaves the nozzle as a bright cone of light and makes the distance between electrode and workpiece electrically conductive.
Depending on the kind of plasma gas and the degree of energy you induce the plasma jet reaches temperatures between 20,000 and 50,000 K. The thermic energy of the arc melts any known kind of metal immediately and partly vaporizes it. The kinetic energy of the plasma jet blows the emerging molt out of the emerging cut kerf. The extremely high energy, which makes the jet come out of of the jet at a supersonic speed, is produced by a sudden expansion of the plasma gas volume as a consequence of the extreme rise in temperature inside the plasma torch.