High-speed impact behavior of cold-sprayed Fe-based amorphous particle on Mg alloy substrate

Amorphous coatings offer substantial enhancements to the surface properties of Mg alloys, particularly concerning wear and corrosion resistance. Cold spray, as a high-speed impact process conducted at low temperatures, demonstrates excellent solid-state forming capabilities for preparing amorphous coatings. However, the excellent properties exhibited by amorphous coatings require comprehensive research on the microstructure evolution of the particle-substrate interface. The results revealed varying degrees of crystallization in the amorphous particle, characterized by obvious crystallization near the particle-substrate interface, where the temperature rise exceeded the crystallization temperature, in contrast to relatively lower crystallization occurring inside the particle. Meanwhile, the high-speed impact led to the formation of a grain-refined layer in the substrate, exhibiting an approximate width of 500 nm, and featuring localized regions of amorphisation. An atomic bonding was achieved in the interfacial area of the particle-substrate where the mixed zone had a width of 40 nm.