Room temperature nanoindentation creep behavior of detonation sprayed Fe-based amorphous coating.

The Fe-based amorphous amorphous coating with a thickness of 150 μm was prepared by detonation spraying. Under a constant strain rate (0.01 s−1 and 0.50 s−1) and a holding time of 50 s, the Fe-based amorphous coatings were subjected to room temperature nanoindentation creep tests with the penetration depth varying from 50 nm to 500 nm, then the depth-dependent creep deformation mechanism of Fe-based amorphous coating during nanoindentation tests were investigated in detail. The results show that the creep responses of coating obviously depend on the indentation penetration depth (h p) and the indentation load rate, i.e., the creep displacement of coating increases with the increase of h p and loading strain rate. This is mainly due to the rapid increase in the shear transition zone volume of the coating as the h p increases, making it easier for the shear band to be excited to nucleate, and results in an obvious creep deformation. Moreover, at high strain rates, the initiation rate of the free volume in the amorphous coating far exceeds its annihilation rate, resulting in a large amount of excess free volume in the amorphous coating, which makes it easier to excite multiple shear bands in the amorphous coating and cause creep plastic deformation. • Fe-based amorphous coatings were deposited by detonation spraying. • The amorphous coating displays a very significant indentation size effect. • Lager shear transition zone volume induces the multiple initiations of shear bands. • Free volume is more likely to accumulate and promote creep at high strain rates. [ABSTRACT FROM AUTHOR]