Plasma jet momentum density
Plasma jet momentum density is the product of density and the square of the flow velocity in the focused plasma jet. It determines the mechanical flushing effect.
Physicochemical Mechanism of Action
The plasma jet momentum density is calculated as the product of the plasma density and the square of its flow velocity. This value indicates how strongly the plasma flushes the surface and how much mechanical energy is transferred to the spot being welded.
Metallurgical Relevance & Welding Risks
A high plasma jet momentum density leads to intensive flushing of the surface, which helps keep the metal clean and free of contaminants. This improves weld quality and prevents pore formation. However, too high a momentum density can also cause thermal overloads that lead to cracks or distortion in the material.
Workshop Practice & Instructions
To achieve an optimal plasma jet momentum density, the flow velocity should be kept between 20 and 40 m/s. The plasma density should be between 1 and 3 g/cm³. Above a momentum density of 50 N/mm² thermal overloads can occur, which risks the weld integrity. So check the settings of the plasma jet system carefully before use and adjust them to the specific materials and components.