Inconel 617 alloy creep life augmentation by graphene transfer coating

Presently, countries are trying to increase their energy efficiency. Therefore, the operating temperatures of very high temperature reactor (VHTR) and high temperature gas-cooled reactor (HTGR) are increasing in order to increase overall efficiency. A metallic material’s intrinsic creep property is a limitation in this scenario. Inconel 617 alloy is a candidate material used in the intermediate heat exchangers of the VHTR and HTGR. Therefore, in this work, graphene, which is a promising ultra-thin material, is utilized as an efficient coating to augment the creep property of the Inconel 617 alloy substrate. The Inconel 617 alloy substrate is coated with graphene via a transfer methodology. The small punch creep test methodology is applied in order to measure the creep lifetime of the specimens. From the experimental results it can clearly be seen that the creep lifetime of the Inconel 617 alloy substrate specimen increases by a significant 5~20 % with the transferred graphene coating compared to the as-received Inconel 617 alloy specimen.