Metastable excited states
Metastable excited states are high-energy atomic states with extended lifetime that facilitate and stabilize ionization processes in the arc.
Physical-Chemical Mechanism of Action
Atoms can be put into metastable excited states in which they absorb more energy than normal. These states are unstable and release their energy quickly, leading to ionization processes.
Metallurgical Relevance & Risks in Welding
These metastable states can be used in arc welding to facilitate the ionization of gas atoms and thus optimize the welding process. Incorrect handling can, however, lead to inconsistent weld quality or higher shielding gas consumption.
Workshop Practice & Action Instructions
Use metastable excited states by adjusting the gas flow and arc voltage accordingly. A lifetime of at least 1 microsecond is typical. Constantly monitor the ionization rate and adjust the settings if needed.