Residual stresses in a Cu-CFC component for thermonuclear application: numerical prediction and experimental evaluation using an indentation technique

The present work concerns the assessment of residual stresses (RS) in a component for thermonuclear applications, made by casting of copper on a carbon fibre-reinforced carbon composite and intended to be subjected to severe cycles of thermal, mechanical and neutron loads. The magnitude of RS left at the interface between the two materials in the production process, due to thermal expansion mismatch, has to be carefully assessed. In the present investigation, the likely spatial distribution of the RS has been predicted first using numerical analysis and has been validated experimentally, then, on the basis of the results of indentation tests performed at the micron scale on the metal layer. It is shown that this simple and fast methodology can return reliable results in the present context.