Enhanced thermal transport and corrosion resistance by coating vertically-aligned graphene on zirconium alloy for nuclear reactor applications

Abstract

Owing to the requirement of higher efficiency, safety reliability and lower maintenance cost for nuclear reactors, the performance improvement of zirconium (Zr) alloy cladding coating materials is becoming increasingly significant. Graphene, with its inherent properties like ultrahigh thermal conductivity, excellent chemical stability, and super-hydrophobicity, has demonstrated enormous potential in the field of corrosion prevention and thermal management, indicating its promising application in cladding materials. Herein, plasma-enhanced chemical vapor deposition (PECVD) was employed for growing vertically-aligned graphene (VG) array on Zr alloy (ZA) substrates. In the deposition process, C2H4 gas was introduced into the reactor as the carbon source and the reactor was kept at a growth temperature range of 650–800 °C, which is 300–400 °C lower than that for traditional graphene synthesis using thermal chemical vapor deposition (CVD). The effects of other growth experimental parameters such as gas flow ratio, radio-frequency power (RF-power), growth temperature, reaction pressure and deposition time were systematically investigated. The corrosion resistance and thermal transport performance of vertical graphene enhanced Zr alloy (VGZA) were studied by using electrochemical corrosion method and heat dissipation test system. The results showed that the samples loaded with vertical graphene could effectively improve the corrosion resistance and heat transport property.