What is the principle of low spatter (STT) welding mode?

The biggest disadvantage of traditional short-circuit transition is the large splashing. During the welding process, when the molten droplet comes into contact with the molten pool, it becomes the connecting bridge between the welding wire and the molten pool, so it is called a liquid bridge, and through this bridge, the circuit is short circuited. Splashing always occurs at the moment when the short circuited bridge breaks. This is because after a short circuit, the current increases sharply, and the liquid metal at the small bridge shrinks rapidly under the action of electromagnetic contraction force, forming a very thin necking. As the current increases and the necking decreases, the current density at the small bridge increases rapidly, heating the small bridge rapidly and causing the accumulation of excess energy, ultimately leading to the vaporization and explosion of the small bridge metal, producing splashing and metal smoke.