IJPEM
Microstructural Evolution and Strengthening Mechanisms of SiC-Reinforced FeCoNiCrAl Coatings by Laser Directed Energy Deposition
Kai Zhang, Weijun Liu/Shenyang University of Technology
- High‑entropy alloys (HEA), SiC particle, Laser directed energy deposition (LDED), Microstructure and properties, Composite coating
- FeCoNiCrAl high-entropy alloys (HEAs) have attracted considerable attention due to their excellent wear and corrosion resistance. However, defects such as cracks and pores tend to form during processing, which significantly limit their industrial applicability. In this study, xSiC/FeCoNiCrAl (x = 0 wt%, 3 wt%, 5 wt%, 10 wt%) composite coatings were fabricated on 1.0503 steel substrates via laser directed energy deposition (LDED). The strengthening mechanisms induced by SiC particles were systematically analyzed, and the effects of different SiC additions on the microstructural evolution of the HEA coatings were investigated. The results show that the incorporation of SiC particles reduces the cracking susceptibility of the HEA coatings, leading to a pronounced decrease in pore-associated cracking. SiC reacts in situ with Cr in the HEA matrix to form Cr7C3 carbides, and the combined contributions of grain-refinement strengthening, dispersion strengthening, and solid-solution strengthening significantly reduce the grain size. With increasing SiC content, the microhardness, wear resistance, and corrosion resistance of the coatings initially improve and then decline, primarily because excessive SiC induces particle agglomeration within the coating. At a SiC content of 5 wt%, the coating exhibits optimal performance: the microhardness reaches a peak value of 561.76 HV0.5 (an 11.24% increase compared with 0 wt%), while the friction coefficient and wear rate decrease to 0.3601 and 2.92 × 10− 4 mm3/N·m, respectively (13.15% and 33.94% reductions compared with 0 wt%). The corrosion resistance also reaches its optimum, and the residual stress attains its minimum value. In summary, the FeCoNiCrAl HEA coating reinforced with 5 wt% SiC demonstrates the best overall hardness, wear resistance, and corrosion resistance under laboratory conditions, indicating promising engineering potential for room-temperature and application-specific environments.
메뉴열기
