Pulsed Arc Frequency Modulation
The targeted variation of the pulse frequency per second to influence droplet size and weld pool hydrodynamics. This serves to avoid lack of fusion and to control the grain structure in the solidification microstructure.
Physical-Chemical Mechanism of Action
Pulsed arc frequency modulation (ILBFM) varies the pulse frequency of the arc, which affects droplet size and weld pool flow. A higher frequency results in smaller droplets and improves the permeability of the shielding gas atmosphere, while a lower frequency produces larger droplets and stabilizes the weld pool flow.
Metallurgical Relevance & Welding Risks
ILBFM influences the grain structure of the solidified weld metal. An optimal frequency leads to a fine, homogeneous grain and improves the mechanical properties of the weld. An inappropriate frequency can cause coarse grain, reduced toughness, and increased susceptibility to cracking.
Shop Practice & Handling Instructions
To use ILBFM effectively, set the pulse frequency between 20 Hz and 100 Hz. A frequency of 50 Hz provides a good balance point for most applications. Constantly monitor droplet size and weld pool hydrodynamics to ensure no lack of fusion occurs and mechanical properties are optimal.