Impact of cyclic thermal shocks on the electrochemical and tribological properties of Fe-based amorphous coating

Fe-based amorphous coatings hold immense potential for marine industries due to their remarkable properties, including high hardness, exceptional corrosion resistance, and outstanding wear resistance. However, their performance under thermal shock conditions, particularly in high-temperature applications, remains a topic requiring further investigation. In this work, a Fe-based amorphous coating with a composition of Fe48Mo14Cr15Y2C15B6 was successfully developed using High-velocity oxygen fuel thermal spraying. To assess the thermal shock resistance of the amorphous coating, we subjected them to thermal cycles at 300 °C for 150 times, followed by cooling in two different mediums: saltwater quenching and air cooling. The results revealed that the coating maintained excellent contact with the substrate and preserved mainly amorphous structure both in the as-sprayed condition and after thermal shocks. Interestingly, the differential scanning calorimetry (DSC) results indicated that the air-cooled samples exhibited greater structural relaxation and crystallization compared to the brine-quenched samples. This microstructure changes in the air-cooled samples resulted in inferior mechanical properties, such as wear resistance and hardness, compared to the brine-quenched and as-sprayed samples.