Effect of B Element Content on the Heterogeneity and Wear Uniformity of (Fe 0.25 Co 0.25 Ni 0.25 Cr 0.125 Mo 0.125 ) 100− x B x Coating by Laser Cladding

Homogeneity has a significant impact on the performance stability and service safety of coatings. (Fe 0.25 Co 0.25 Ni 0.25 Cr 0.125 Mo 0.125 ) 100− x B x ( x = 14, 17, 20) coatings were prepared by laser cladding; afterward, the effects of B element content on the heterogeneity and wear uniformity of the coating were studied under the same friction conditions. B element, decreasing from the outside to the inside of the coating, promotes the formation of the FCC (face-centered cubic) phase and boride precipitates, which lead to the BCC (body-centered cubic) phase separation and refinement. When the content of B element is 14%, with an appropriate proportion of FCC, BCC, and boride precipitate phases, the coating not only has the best wear resistance due to its higher hardness and satisfactory toughness, but also has the best performance uniformity because of a small phase and hardness gradient. The average COFs are 0.4586, 0.3963, and 0.4108 with 0.48 × 10 8 , 0.3 × 10 8 , and 0.36 × 10 8 μ m 3 volume losses corresponding to the surface, middle, and bottom section of B 14 coatings.