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PLASMA CUTTING AND GOUGING Non-ferrous metals such as aluminum and copper also have refractory oxides coverings, which prohibit normal flame cutting. In addition they also have high thermal conductivity. Stainless steel cannot be flame cut with standard flame cutting equipment and technique because of the refractory chromium oxide formed on the surface.

So how can we overcome these nature’s physical laws for a process to work on a given metal? Simply by changing process from chemical (Flame cutting) to an electric (Plasma cutting).

In Plasma cutting only one condition must apply in order to perform cutting: 1) The metal must be electrically conductive.

What is Plasma?

One common description of plasma is that it is the fourth state of matter. We normally think of the three states

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Plasma, the fourth state of matter

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of matter as solid, liquid, and gas. For most commonly known element, water these three states are ice, water and steam. The significant difference between these states relate to the energy level. If we add energy in the form of heat to ice, the ice melts and the result is water, a liquid. If we add more energy to water, it vaporizes to the gas we normally call steam. By adding even more energy to the steam the gas become ionized. This ionization process causes the gas to become electrically conductive. This electrically conductive ionized gas is called plasma.

(At a temperature of between 2000°C (3600°F) and 10000°C (18000°F) a process of ionization and dissociation of the gas molecules take place. The molecules are split in molecular and atomic ions and free electrons. When this happens, the gas, which has now become plasma, is electrtrically conductive because free electrons are available to carry current). The process utilizes the electrically