Selection principle of ultra-high speed laser cladding powder
1. The performance of the powder should meet the required requirements, such as: wear resistance, oxidation resistance, high temperature resistance, corrosion resistance and other properties.
2. With good solid fluidity, powder fluidity and powder shape, particle size distribution, surface state and powder humidity and other factors related.
(1) Spherical powder has the best fluidity;
(2) The powder feeding method generally uses ordinary particle size and coarse powder;
(3) Very fine powder and ultra-fine powder due to poor solid fluidity, special powder feeder must be used to ensure uniform powder delivery.
(4) The fluidity of the powder is poor when it is wet, and attention should be paid to drying when it is used.
3. The thermal expansion coefficient and thermal conductivity of the powder material should be as close as possible to the workpiece material to reduce the residual stress in the cladding layer.
4. With good wettability. The wettability is related to the surface tension. The smaller the surface tension is, the smaller the wetting Angle is, the better the liquid fluidity is, and the smooth cladding layer is easy to be obtained. Ni element can improve the wettability of powder.
5. Should have good cladding technology, such as good slag, degassing, and gas insulation performance;
(1) Self-fluxing alloy metal powder is widely used, containing B, SI, with deoxidation, degassing, slagging and other functions.
(2) The deoxidation product should form a slag with small proportion and low melting point to cover the surface of the liquid metal, which protects the surface to prevent slag inclusion, porosity, oxidation and other defects.
6. The melting point of alloy powder should not be too high or too low.
(1) The lower the melting point of the powder and the better the liquid fluidity, the easier it is to control the dilution rate of the cladding layer, which is beneficial to obtaining a smooth and good-quality cladding layer.
(2) However, the powder melting point is too low, which is easy to overburn the cladding layer.
Xi'an Guosheng Laser Technology Co., Ltd. is a high-tech enterprise specializing in R&D, manufacturing and sales of automatic laser cladding machine, high-speed laser cladding machine, laser quenching machine, laser welding machine and laser 3D printing equipment. Our products are cost-effective and sold domestically and abroad. If you're interested in our products, please contact us at bob@gshenglaser.com.