中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 33 No. 1 January 2023 |
（1. State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China;
2. Department of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China;
3. Shanghai Institute of Laser Plasma, China Academy of Engineering Physics (CAEP), Shanghai 201800, China;
4. School of Automotive and Traffic Engineering, Jiangsu University of Technology, Changzhou 213001, China;
5. Key Laboratory for Laser Plasmas (MOE), Collaborative Innovation Center of IFSA (CICIFSA), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:An active suppressing method of laser-induced plasma was proposed to optimize the crystal structure and tribological properties for the surface laser sintering (SLS) of Ni30Cr25Al15Co15Mo5Ti5Y5 high-entropy alloy (HEA) coatings using a pulsed laser with various shielding gases. The results indicate that electron temperature (Te) and the plasma jet volume with no shielding gas or in He atmosphere were higher than those in Ar-He atmosphere. Well- defined phase transitions and significant metal atom diffusion occurred in SLS, and metallurgical bonding occurred with the precipitation of α-AlFe3, α-AlNi, and γ-AlFe2Ni. The lower energy absorbed by the plasma via inverse bremsstrahlung (IB) strengthened interactions between laser and HEA, increasing the microhardness, and reducing the dynamic friction coefficient. This elucidates the crucial influence of plasma control on laser-based additive manufacturing.
Key words: laser-induced plasma; surface laser sintering (SLS); electron temperature (Te); inverse bremsstrahlung absorption (IB); high-entropy alloy (HEA); residual stress
