Brief introduction of laser cladding preset method (laser remelting) and synchronous powder feeding method

       The powder feeding of laser cladding includes preset method (laser remelting) and synchronous method according to the different supply methods of alloy materials.



The presetting method means that the alloy material to be clad is pre-covered on the surface of the substrate in a certain way, and then a laser beam is used to scan the surface of the alloy pre-cladding layer. The surface of the pre-cladding layer absorbs laser energy to increase the temperature and melt. At the same time, the surface heat is transferred to the interior through heat conduction, so that the entire alloy pre-cladding layer and a part of the base material are melted. After the laser beam leaves, the molten metal rapidly solidifies on the surface of the material to form a metallurgically bonded alloy cladding layer.



Pre-alloyed materials are usually powders. The preset methods include brush bonding and thermal spraying. The brushing bonding method is to blend the alloy powder into a paste and brush it on the surface of the substrate with a binder, and it is difficult to obtain a coating with uniform thickness; thermal spraying includes flame spraying, arc spraying and plasma spraying, and its main advantage is efficiency High, the coating thickness is uniform and firmly combined with the substrate, the disadvantage is that the powder utilization rate is low, and special equipment and technology are required.



The synchronous method refers to using a special conveyor to directly send the alloy material into the laser action area, and under the action of the laser, the alloy material is melted on the surface of the substrate to form an alloy cladding layer. The synchronous conveying method can use alloy wire and alloy powder, the process engineering is simple, and the controllability is good, but the deposition efficiency is low when powder materials are used.