Enhanced Corrosion and Wear Resistances of Zr-based Alloy Induced by Amorphous/Nanocrystalline Coating

Abstract

To improve corrosion and wear resistances of the Zirconium(Zr) based alloys which are widely applied in nuclear reactors and chemical corrosion-resistant equipment, a new surface modification scheme was designed to deposit a Zr₇₅Cu₂₅ coating on Zr substrate by using magnetron sputtering technique. The microstructure and the phase composition were characterized by scanning electron microscope, transmission electron microscope, and X-ray diffraction measurements. The tribological properties and the corrosion resistance were investigated by performing reciprocating tribo-tester and electrochemical tests, respectively. It is found that the Zr₇₅Cu₂₅ coating is made up of a mixture of amorphous and α-(Zr) nanocrystalline phases. The nanocrystalline particles with a size of 5–10 nm are homogenously dispersed in the amorphous matrix. The Zr₇₅Cu₂₅ coating shows excellent tribological properties, due to the dispersion strengthen caused by the homogeneous distribution of α-(Zr) nano-size particles among the amorphous matrix. In addition, it is revealed that the Zr₇₅Cu₂₅ coating makes the Zr substrate exhibit excellent corrosion resistance, due to the robust passive film with a compact structure of the amorphous/nanocrystalline mixture.

Keywords

coating materials / magnetron sputtering / microstructure / vorrosion resistance / tribological property