Chemical compatibility between ARAA alloy and lithium meta-titanate breeder material

Abstract

Chemical compatibility between reduced activation ferritic-martensitic steel, ARAA, and lithium meta-titanate breeder was investigated under operating conditions; high temperature and helium purge gas including a low concentration of hydrogen. ARAA specimens were embedded inside lithium meta-titanate powder and compacted under a load of 200MPa to form disk-shaped samples. The samples were heated at 550°C for up to 1000h in helium with up to 1% hydrogen atmosphere to simulate a fusion breeding blanket environment. The surface of the ARAA specimen was chemically reacted with the lithium meta-titanate breeder to form an oxide layer. The thickness of the oxide layer increased as the heating time increased. The hydrogen in the purge gas made the oxide layer thinner due to the reaction with oxygen in the oxide layer. The growth phenomena of the oxide layer were evaluated.