Tribological performance of the Fe-based fully amorphous and amorphous/crystalline coatings

In this research, fully amorphous and amorphous/crystalline (A/C) Fe-based coatings were explored for high-temperature tribological applications. The commercially available gas atomized feedstocks were sprayed using high-velocity oxygen fuel (HVOF) processes, and microstructural, mechanical and tribological behaviour of the coatings were investigated and compared. The fully amorphous Fe-based amorphous coating exhibited higher wear resistance at 600 °C than room temperature with high thermal stability and performed superior to A/C coatings at both temperatures. Detailed analysis of worn surfaces demonstrated that fully amorphous coatings were dominated by oxidative and adhesive wear, whereas A/C coating suffered abrasive and surface fatigue wear. A thick oxide glaze layer formed onto the worn surface accompanied by enhanced high-temperature mechanical properties cumulatively protected fully amorphous coatings from severe wear loss. Therefore, the exceptional wear resistance and structure retention ability of the investigated Fe-based amorphous coating establishes promising outlooks as high-temperature protective coatings for tribological applications.