Plasma

From GAWDAwiki

Plasma is a form of matter in which many electrons move freely among the nuclei of atoms. It has been called the fourth state of matter, implying its distinction from solids, liquids and gases. ^[1]

Forming a Plasma

Electrons in solid, liquid and gaseous matters typically remain with a particular atomic nucleus, except in the presence of electric current flows. In plasmas, many electrons have energy levels so high that a single nucleus cannot hold them. The transfer of electrons leads to ionization of the atoms. An ionized gas has the unique ability among gases to conduct an electric current. Extreme heat can lead to super-ionized gas, also known as plasma, which can conduct large, sustained electric currents.^[1]

Welding Applications

Plasma is used in plasma arc welding and cutting. The process is similar to TIG welding, but the electrode is contained in the body of the torch, allowing for the separation of the plasma arc and the shielding gas envelope. The arc is constricted when plasma is forced through a fine-bore copper nozzle.^[2]