Laser welding and arc welding are two commonly used methods for mold repair.

TIG welding is a kind of arc welding, which uses the arc burning between the continuously fed welding wire and the workpiece as the heat source, and the gas shielded arc sprayed from the torch nozzle is used for welding. At present, argon arc welding is a commonly used method, which can be applied to most major metals, including carbon steel and alloy steel. MIG Welding is suitable for stainless steel, aluminum, magnesium, copper, titanium, zirconium and nickel alloys. Due to its low price, it is widely used in mold repair welding, but it has the disadvantages of large welding heat affected area and large solder joints. Precision mold repair has been gradually replaced by laser welding.

Laser welding is a kind of high-energy beam welding. Laser welding is a welding that uses a laser beam focused by high-power coherent monochromatic photon flow as a heat source. This welding method usually includes continuous power laser welding and pulsed power laser welding.

The advantage of laser welding is that it does not need to be carried out in a vacuum, but the disadvantage is that the penetration is not as strong as electron beam welding. Laser welding can carry out precise energy control, so it can realize the welding of precision devices. It can be applied to many metals, especially the welding of some difficult-to-weld metals and dissimilar metals. At present, it has been widely used in the repair of molds.

Using non-consumable electrodes and shielding gas, it is often used to weld thin workpieces, but the welding speed is slow, and the heat input is much larger than that of laser welding, which is prone to deformation. , The weld cooling rate is fast, the weld metal properties change little, and the weld is hard.

The welding of precision molds is different from the welding of other parts, and its requirements for quality control are very strict, and the repair cycle of the workpiece must be as short as possible.

The traditional argon welding has a large heat-affected area, and the probability of collapse and deformation of the welding periphery is very high. For molds with high precision requirements and large welding area, they must be preheated and welded at a specific temperature. Cooling down for annealing treatment, so the cost and time cannot be accepted by users; and cold welding has defects such as weak welding and falling off. However, laser welding does not have the shortcomings of argon welding and cold welding, so it is gradually widely used.