Resistance Welding
It is used to weld thin metal parts. The workpiece is clamped between two electrodes, and a large current is applied to melt the surfaces where the electrodes contact, thus welding is achieved through the workpiece's resistance heating. The workpiece is prone to deformation. Resistance welding joins from both sides, while laser welding only joins from one side. The electrodes used in resistance welding require frequent maintenance to remove oxides and metal adhering to the workpiece. Laser welding of thin metal lap joints does not involve contact with the workpiece, and the laser beam can penetrate areas difficult to reach with conventional welding. Welding speed is also fast.
Argon Arc Welding
Uses non-consumable electrodes and shielding gas, often used to weld thin workpieces, but the welding speed is slower, and the heat input is much greater than laser welding, making deformation more likely.
Plasma Arc Welding
Similar to argon arc welding, but its torch generates a compressed arc to increase arc temperature and energy density. It is faster and has a greater penetration depth than argon arc welding, but less so than laser welding.
Electron beam welding
It relies on a beam of accelerated, high-energy-density electrons to bombard the workpiece, generating enormous heat within a small, dense area on the workpiece surface, creating a "keyhole" effect, thereby achieving deep penetration welding. The main disadvantages of electron beam welding are the requirement for a high-vacuum environment to prevent electron scattering, the complexity of the equipment, the limitation on the size and shape of the workpiece by the vacuum chamber, and the strict requirements for the assembly quality of the workpiece. Non-vacuum electron beam welding can also be performed, but poor focusing due to electron scattering affects the results.