Mechanical and electrochemical properties of PEO coatings on zirconium alloy

Zirconium and its alloys are frequently used in many engineering and scientific applications owing to their unique mechanical, chemical and thermal properties. However, zirconium and its alloys may undergo corrosion and wear under some circumstances. Severe operating conditions demand improvement of wear and corrosion resistance of these alloys. In this study, plasma electrolytic oxide coatings were produced on Zr-702 alloy at two different process times then corrosion and wear behaviours of coatings were evaluated. Test results showed that the application of coatings on Zr-702 improved both corrosion and wear resistance remarkably. It has been observed that the coating produced in a longer time exhibited higher load-carrying capacity thus provided better wear resistance than the coating formed in a shorter time. On the other hand, decreasing the PEO process time reduced the structural defects in the coating and led to increased corrosion resistance