Evidence of damage in carbon fibre composite tiles joined to a metallic heat sink under high heat flux fatigue

TL;DR

This study demonstrates that carbon fibre composite tiles bonded to metallic heat sinks can withstand high heat flux fatigue, with the bond showing remarkable durability up to 3330 cycles and damage primarily due to design and material limitations.

Contribution

The paper provides empirical evidence that Active Metal Casting bonds are suitable for high heat flux applications in fusion devices, with detailed analysis of fatigue resistance and failure modes.

Findings

Bond withstands up to 3330 cycles at 10 MW/m²

No tile detachment observed under high heat flux fatigue

Damage at higher fluxes linked to design and material, not the bond

Abstract

The two years experience with Active Metal Casting flat bonds shows that this technology is suitable for the heat fluxes expected in Tore Supra (10 MW/m${}^2$). Tests were pursued up to 3330 cycles, with elements still functional. At higher heat fluxes, fatigue damage is observed, but the bond resists remarkably well with no tile detachment. Examination of such deliberately damaged bonds showed distributed cracking, proving the absence of any weak link. The limitations to those higher heat fluxes are more related to the design and the base materials than to the bond itself.