Some common sense about laser cladding, explained by a hydraulic support laser cladding manufacturer

　　 Laser cladding of hydraulic support Manufacturers believe that laser cladding technology was developed in the 1970s, with a laser power density distribution range of 104~106W/cm2, between laser quenching and laser alloying. Laser cladding is the rapid heating and melting of alloy powder or ceramic powder on the surface of the substrate under the action of a laser beam. After removing the laser beam, self-excited cooling forms a surface cladding layer with extremely low dilution rate, metallurgically bonded to the substrate material.

　　 Laser cladding of hydraulic support Manufacturers believe that during the entire laser cladding process, there is interaction between the laser powder and the substrate, namely the interaction between the laser and the powder, the laser and the substrate, and the powder and the substrate.

　　(1) Manufacturers of laser cladding for hydraulic supports believe that the interaction between the laser and the powder When the laser beam passes through the powder, part of the energy is absorbed by the powder, causing the energy reaching the substrate surface to attenuate; however, due to the thermal effect of the laser, the shape of the powder changes before entering the metal melt pool. Depending on the amount of energy absorbed, the powder forms are molten, semi-molten, and unmolten.

　 　(2) The interaction between the laser and the substrate melts the substrate. The heat of the melt pool comes from the energy attenuated by the interaction between the laser and the powder, which determines the penetration depth of the substrate and thus affects the dilution of the cladding layer.

　　(3) Manufacturers of laser cladding for hydraulic supports believe that the interaction between the powder and the substrate After the alloy powder is ejected from the powder feeding port, it diverges under the disturbance of the mechanical factors of the carrier gas, causing some of the powder to not enter the melt pool of the substrate metal, but to be impacted by the beam onto the unmelted substrate and sputtered. This is an important reason for the low powder utilization rate of side-feeding laser cladding.

　　Manufacturers of laser cladding for hydraulic supports believe that laser cladding technology can obtain a surface cladding layer that is metallurgically bonded to the substrate, has a low dilution rate, has a small heat-affected zone on the substrate, and can be locally cladded. Since the 1980s, the research field of laser cladding technology has been further expanded, including cladding layer quality, microstructure and service performance, alloy selection, manufacturability, thermophysical properties, and computer numerical simulation.

　　Manufacturers of laser cladding for hydraulic supports believe that alloy powder is a commonly used material for laser cladding. According to the different powder feeding methods of the cladding material, laser cladding can be divided into pre-placed laser cladding and simultaneous powder feeding laser cladding.

　　(1) Pre-placed laser cladding: The cladding material is pre-placed on the cladding part of the substrate surface, and then melted by laser beam irradiation scanning. The cladding material is added in the form of powder, wire, and plate, among which powder coating is more commonly used. The main process flow of pre-placed laser cladding is: pre-treatment of the substrate cladding surface, pre-placement of cladding material, preheating, laser melting, and post-heat treatment.

　　(2) Laser cladding of hydraulic support Manufacturers believe that simultaneous powder feeding laser cladding directly feeds the cladding material into the laser beam, so that powder feeding and cladding are completed simultaneously. The cladding material is mainly fed in the form of alloy powder, and a small part is also fed in the form of wire or plate. The main process flow of simultaneous powder feeding laser cladding is: pre-treatment of the substrate cladding surface, powder feeding, laser melting, and post-heat treatment. Simultaneous powder feeding laser cladding can be divided into side powder feeding and coaxial powder feeding. The laser beam irradiates the substrate to form a liquid melt pool, and the alloy powder is ejected from the powder feeding nozzle under the drive of the carrier gas and enters the liquid melt pool under the action of the laser. As the powder feeding nozzle and the laser beam move synchronously, a cladding layer is formed.