Ionisation Potential Influence
Ionization potentials of shielding gases influence arc voltage and thermal performance. Gases with high potential require higher voltages to maintain the plasma.
Physical-Chemical Mechanism of Action
The influence of ionization potential concerns the energy required to ionize an atom or a molecular cluster. Gases with high ionization potential require more energy to create and maintain plasma spheres in the arc.
Metallurgical Relevance & Risks in Welding
Gases with low ionization potential (such as argon) require less voltage, resulting in lower arc voltage. However, this can lead to a weaker plasma and lower thermal performance, which can affect weld quality. Gases with high ionization potential (such as helium) require higher voltages, resulting in higher arc voltage and better thermal performance, but also increased power consumption and lower efficiency.
Workshop Practice & Instructions
Choose shielding gases with an ionization potential that matches the desired arc voltage. For high-performance applications like deep penetration welding, a gas with high ionization potential (e.g., helium) is suitable. For low power requirements and energy savings, a gas with low ionization potential (e.g., argon) is better. Ensure the arc voltage is set accordingly to generate the desired plasma.