Microstructural and mechanical properties of Al-base coated EUROFER-97

Abstract

Coolant-facing alloys in a tokamak will face harsh environments due to the synergistic effect of flowing coolant, dynamic mechanical loading, ionising radiation, and tritium embrittlement. Reduced activation ferritic/martensitic (RAF/M) EUROFER-97 is the primary candidate as the structural alloy for the breeder blanket to be used in DEMO reactor. Under fusion-like conditions, coatings are required to improve both its corrosion properties and act as a tritium permeation barrier (TPB) layer. In this study, Al-base self-passivating coatings have been investigated as possible solution to provide protection against corrosion and act as TPB layer. The aim of this study was to assess the adhesion properties between different self-passivating Al-base coatings as electroplated and chemical vapour deposited (CVD) coatings on a RAF/M EUROFER-97 under strain. These studies showed the high ductility of pure electroplated Al-coatings, whereas both CVD coatings cracked under the applied strain.

Keywords

• EUROFER-97
• Aluminide
• Alumina
• Coatings
• Breeder blanket
• Self-passivating coating