What is Laser Cladding Equipment?
Laser cladding is a new surface modification technology. It uses different filling methods (synchronous powder feeding or preset powder) to place the selected coating material on the surface of the coated substrate, and irradiates with the high-energy laser beam to form a metallurgical bond with the matrix material. Improve the heat resistance, corrosion resistance, wear resistance, oxidation resistance and other characteristics of the surface of the base material.
two-step method (preset method)
In this method, the cladding material is placed on the working surface, and then it is melted by a laser and condensed to form a cladding layer. The way to preset the cladding material includes:
- Pre-coating layer: Usually applied by hand, it is economical and convenient. It is prepared by placing the powder for cladding on a surface of the workpiece with a binder, drying it, and then performing laser cladding treatment. However, this method has low production efficiency and inconsistent cladding thickness, which is not suitable for mass production.
- Preset sheet: The powder of the cladding material is molded into a sheet by adding a small amount of binder, placed on the workpiece to be welded, and then subjected to laser treatment. The method has high powder utilization rate and stable quality, and is suitable for some deep-hole parts, such as a small size valve body, and can be processed by this method to obtain a high-quality coating.
2. one-step method (synchronization method)
This is a process of feeding a cladding material to a laser action region while the laser beam is irradiating the workpiece, and it is divided into two ways.
Simultaneous powder feeding method: a single spray powder feeding device (see figure) is used to feed a single or mixed powder into the molten pool, and the thickness of the cladding layer can be adjusted by controlling the powder feeding amount and the laser scanning speed. Since the loose powder has a large absorption rate of laser light and high thermal efficiency, a thicker cladding layer than other methods can be obtained, and automation is easy. This method is used more in actual production abroad.
Synchronous wire feeding method: Although the process principle of this method is the same as the synchronous powder feeding method, the cladding material is pre-processed into a wire material or a filled wire material. The method is convenient and does not waste materials, and it is easier to ensure the uniformity of the composition of the cladding layer, especially when the cladding layer is a composite material, the coating quality is not affected by the specific gravity or the particle size of the powder, and the wire is passed through the wire. Fine processing of preheating can increase the cladding rate. However, the surface of the wire is smooth, the reflection of the laser is strong, and the laser utilization rate is relatively low; In addition, the manufacturing process of the wire is complicated, and the wire type and specifications are small.