Ionisation Voltage of Shielding Gases
The ionization voltage is the minimum energy needed to ionize a gas atom. It influences the conductivity of the arc plasma. Gases like argon and helium have different ionization voltages.
Physical-Chemical Mechanism of Action
The ionization voltage is the energy required to split a gas atom into a positively charged ion and a free electron. This process is crucial for the conductivity of the arc plasma in the welding process.
Metallurgical Relevance & Risks in Welding
The ionization voltage affects the stability and behavior of the plasma. Gases with lower ionization voltage like helium are easier to ionize and lead to a more stable plasma, enabling better conductivity and a more precise weld profile. Gases with higher ionization voltage like argon require more energy to ionize and can become unstable if voltage is insufficient, leading to failures or irregular weld quality.
Workshop Practice & Instructions
Choose the gas with the appropriate ionization voltage depending on the application. For high-performance processes and precise control, helium is often the choice because it is easier to ionize. For simple or less exact welding processes, argon can be used, but ensure the voltage is high enough to maintain a stable plasma.