| Surface tension transition (STT) | To improve the energy accumulation of droplets, the welding current can be reduced instantaneously and the spatter can be effectively reduced before the droplet short circuit liquid bridge bursts | Short-circuit transition is required and robustness is insufficient |
| Pulse GMAW | Improving droplet energy accumulation, peak current transfer droplet and base dimension arc, reducing average heat input | The thermal input of the peak value of pulse impacts the substrate |
Droplet excitation | Improving droplet energy accumulation, using droplet oscillation inertia force to promote droplet transition, reducing pulse peak current and improving transition robustness | Precise matching of droplet oscillation phase is required |
Cold metal transfer (CMT) | By introducing mechanical force, the welding wire can be fed back and forth, the short-circuit droplets can be broken mechanically, there is no spatter transition, and the heat input is low | The dynamic performance of the motor is limited, and the torch is complex and bulky |
| Magnetic control GMAW | The external magnetic field is introduced to add Lorentz force to increase the transition frequency | The effect is weak |
| Bypass GMAW | By introducing the bypass arc with additional electromagnetic force, the droplet transition can be significantly promoted | Multi-electrode accessibility is limited, high arc length avoids arcing |
Ultrasonic GMAW | Welding arc space composites ultrasonic field, while the ultrasonic radiation force promotes the droplet transition and the droplet transition is often under the longer arc | Droplet size can be controlled, but it is difficult to provide directivity |
Laser enhancement GMAW | Laser evaporation reaction is introduced. Pulsed laser irradiates droplets. Laser impulse promotes droplet detachment and realizes controllable transition | The direction of evaporation reaction force is directly related to the surface morphology of droplets, so it is difficult to accurately control the direction of force |