Effect of Y 2 O 3 Content on Microstructure and Wear Resistance of Laser Cladding Layer of Stellite-6 Alloy.

Laser cladding technology is an effective surface modification technique. In order to prepare coating with excellent properties on the surface of the cold heading die punch, stellite-6 cladding coating with different proportions of Y₂O₃ was prepared on the surface of W6Mo5Cr4V2 high-speed steel using laser cladding technology in this paper. The effects of different Y₂O₃ contents on the macroscopic morphology, microstructure, phase analysis, microhardness, and tribological properties of the stellite-6 coatings were investigated. It was determined that the optimal Y₂O₃ content for the stellite-6 powder was 2%. The results showed that the coating with 2%Y₂O₃ had the least number of pores and cracks and exhibited good surface flatness when joined. The microstructure became finer and denser, composed mainly of branch, cellular, equiaxed, and columnar grains. The coating consisted mainly of γ-Co, Fe-Cr, and Co₃Fe₇ strengthening phases, indicating good metallurgical bonding between the coating and the substrate. The average microhardness reached 539 HV when 2%Y₂O₃ was added, a 15.2% increase compared with the unmodified multilayer coating. The friction coefficient of the clad layer was 0.356, a 21.8% improvement over the unmodified stellite-6 coating. The average worn area of the cross-section was 3398.35 μm², a reduction of approximately 27.8% compared with the unmodified stellite-6 clad layer. The wear surface primarily exhibited abrasive wear, with fewer cavities and a smoother surface. [ABSTRACT FROM AUTHOR]