Coaxial Laser Cladding of Fe-Cr-Ni Alloy Powders on to Al 2024 Alloy
T. Sun, L-L. Li and T. Gao
In order to reveal the properties of Fe-based powders laser clad with a fibre laser on Al 2024 alloy, the effects of laser power, scanning speed and powder feeding voltage were studied. Spray-dried sintered 64.57% Fe-Cr-Ni alloy powders were directly coated on to Al 2024 alloy by coaxial laser cladding. A large number of single-track and multi-track laser cladding experiments were executed to improve sample forming quality. The microstructure, elemental distribution and hardness of the cladding sample were studied. The influence of overlapping ratio on the flatness of the cladding layer was researched and the optimal overlapping ratio was determined. The damaged area of injection mould for cooling cap of air conditioning in a car was repaired with the coaxial laser cladding technique under the condition of optimized parameters. The research shows that the number of laser cladding passes and the repetition rate have a significant effect on the cladding results. It is a practical method to use Fe-based powder to repair faults on Al-based substrates.
Keywords: Fibre laser, Al 2024, Fe-Cr-Ni alloy, coaxial laser cladding, microstructure, elemental distribution, hardness