Effect of low-dose Xe20+ ion irradiation on the deformation behavior of the magnetron sputtered Cr coatings under nanoindentation

The magnetron sputtered Cr coatings on zirconium (Zr) alloy substrates were irradiated by the 5 MeV Xe20+ ions at room temperature, followed by the studies on microstructure, mechanical properties, and deformation behavior. The coatings exhibit structural integrity without blistering or flaking effects after the 1 x 1014 ions/ cm2 irradiation, but the irradiation caused the surface particle refining and the hardening effect. The hardness of the irradiated coating increased -60% and the indentation modulus decreased -10%. Moreover, the microstructural characterization was conducted on the tetrahedron indentations by using scanning electron microscope (SEM), atomic force microscope (AFM), and transmission electron microscope (TEM). A piling-up of matter was observed in the indentation of the as-deposited coating, whereas some micro-cracks appeared near the indentation zones on the irradiated coatings. The cross-sectional TEM micrograph of an indentation further revealed the disordering of lattices and the bending of columns in the irradiated area, maybe for the irradiation made the column interface strong so that the column sliding hardly occurred.

Automated summary

The Cr coatings deposited by magnetron sputtering on zirconium alloy substrates were irradiated by 5 MeV Xe20+ ions, leading to surface particle refining and hardening effects. The microstructure of the coatings remained intact after irradiation, exhibiting increased hardness and decreased indentation modulus. However, micro-cracks were observed near the indentation zones on the irradiated coatings, indicating some structural changes caused by the radiation.