Light cladding refers to the process of synchronizing or presetting materials by adding external materials to the molten pool formed by laser irradiation on the matrix, and making the two rapidly solidify together to form the coating layer.

Laser cladding features: the cladding layer has low dilution but strong bonding force, and is metallurgical combined with the substrate, which can significantly improve the wear resistance, corrosion resistance, heat resistance, oxidation resistance or electrical characteristics of the surface of the substrate material, so as to achieve the purpose of surface modification or repair, meet the specific performance requirements of the surface of the material and save a lot of material costs.Compared with surfacing, spraying, electroplating and vapor deposition, laser cladding technology has many advantages, such as smaller dilution, compact structure, better bonding between coating and substrate, more suitable cladding materials, larger variation of particle size and content, etc. Therefore, laser cladding technology has a broad application prospect.

From the current application of laser cladding, it is mainly used in three aspects: first, the surface modification of materials, such as steam turbine blades, rollers, gears, etc.;Second, the surface repair of the product, such as rotor, mold, etc.Relevant data show that the strength of the repaired parts can reach more than 90% of the original strength, and the repair cost is less than 1/5 of the replacement price. More importantly, the repair time is shortened, and the problem of quick repair of rotating parts which must be solved for the continuous and reliable operation of major complete sets of equipment in large enterprises is solved.In addition, laser cladding superwear-resistant alloy on the surface of key parts can greatly improve the service life of the parts without deformation of the surface.The laser cladding treatment on the surface of the die can not only improve the strength of the die, but also reduce the manufacturing cost by 2/3 and shorten the manufacturing cycle by 4/5.Three, laser additive manufacturing.By synchronous feeding of powder or wire, laser cladding is carried out layer by layer, and then the parts with three-dimensional structure are obtained.This technology can also be called laser melting deposition, laser metal deposition, laser direct melting deposition, etc. [1].

Cladding materials: laser cladding materials widely used mainly include: nickel base, cobalt base, iron base, titanium alloy, copper alloy, granular metal matrix composite materials, ceramic materials, etc.