Corrosion behavior and wear resistance of Zr-2.5Nb alloy after thermal oxy-nitriding treatment

Nitrogen oxides of metals are hard and have excellent electrical conductivity, and have a wide range of applications in structural materials and industrial production. The aim of this study is to modify the surface thermal treatment of alloys and optimise the process parameters so that the corrosion and wear resistance of alloys can be significantly improved, extending service life. The Zr-2.5Nb alloys were experimentally selected for thermal treatment from 700 to 1200 ? in a vacuum tube furnace under N-2 and O-2. The morphology and surface element distribution were investigated. ZrN, ZrO2, NbN, and Nb2O5 composite film were generated on the alloy surface, which was relatively thick and dense. The impedance and polarization curves of specimens were investigated in NaCl and HCl solutions. All of the treated specimens exhibited good corrosion resistance and pitting resistance compared with that of the substrate. Results of Vickers hardness and friction wear test performance revealed significant quality improvement. Both wear volume and wear mass decrease gradually. The thermodynamics of the thermal treatment process was analyzed via the calculation of the Gibbs free energy.

Automated summary

This study aims to improve the corrosion and wear resistance of alloys through modified surface thermal treatment. By optimizing the process parameters, a thick and dense composite film was successfully generated on the alloy surface, leading to significant improvement in corrosion resistance and wear resistance. The study highlights the potential of thermal treatment for extending the service life of alloys.