Thermal shock behavior of Fe-based amorphous coatings under cryogenic cycling treatment

Abstract

Fe-based amorphous coatings were deposited on invar alloy substrates by ADM-4D detonation-gun with different spraying parameters. The cryogenic cycling treatment (CCT) from 0 to 60 cycles was performed on the coatings to investigate the effects of CCT on the thermal shock behaviors of the coatings. In combination with finite element analysis and in-situ tensile test, the study revealed that the thermal shock behaviors of the coatings are primarily influenced by porosity and interfacial oxidation. The presence of pores in the sprayed coatings helps dissipate strain energy, thereby slowing down the initiation and propagation of cracks in the CCTed Fe-based ACs. On the other hand, interfacial oxidation causes a sudden increase in the maximum thermal stress in the oxidation regions, which is the primary cause of cracks in the coatings.