Mould plays an extremely important role in modern industry, and its quality directly determines the quality of products. It is an urgent technical problem for many enterprises to improve the service life and accuracy of molds and shorten the manufacturing cycle of molds. However, failure forms such as corner collapse, deformation, wear and even fracture often occur in the use of dies. Therefore, it is necessary to repair the mold. There are many ways to repair the mold, such as EDM, argon arc welding, laser surfacing, brush plating and so on. The repair of argon arc welding is to use the burning arc between the welding wire and the workpiece as the heat source, and the gas sprayed from the nozzle of the welding gun protects the arc for welding. At present, argon arc welding is a common method, which can be applied to most major metals, including carbon steel and alloy steel. Metal inert gases are suitable for stainless steel, aluminum, magnesium, copper, titanium, zirconium and nickel alloys. Because of its low price, it is widely used in mold repair welding. However, due to the shortcomings of large heat affected area and large solder joints, laser welding has been gradually replaced in the repair of precision molds. Brush plating repair brush plating technology adopts special DC power supply equipment, and the positive pole of the power supply is connected with the plating pen as the anode during brush plating; During brush plating, the negative electrode of the power supply is connected to the workpiece as a cathode. High-purity fine graphite blocks are usually used as anode materials for electroplating pens.

The graphite block is wrapped with cotton and wear-resistant polyester cotton sheath. When working, the power supply module is adjusted to a proper voltage, and the plating pen dipped in plating solution moves back and forth on the surface of the repaired workpiece at a certain relative speed and maintains a certain pressure until a uniform and ideal metal deposition layer is formed. Due to the contact position between the plating pen and the surface of the repaired workpiece, the metal ions in the plating solution diffuse to the surface of the workpiece under the action of electric field force, and the electrons obtained on the surface are reduced to metal atoms.

Laser surfacing repair laser welding is welding with a laser beam focused by a high-power coherent monochromatic optical sub-stream as the 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 vacuum, but the disadvantage is that the penetration is not as strong as that of electron beam welding. Accurate energy control can be carried out during laser welding, so the welding of precision devices can be realized. It can be applied to a variety of metals, especially to solve the welding of some difficult-to-weld metals and dissimilar metals. At present, it has been widely used in mold repair.