Development of low-Z divertor plate material with functionally gradient material layer

The use of functionally graded layers (FGLs) for plasma facing components (PFCs), owing to moderate or piecewise transition in material properties from low-Z surface materials to metal substrates, can provide reduction in thermal stresses, and also provide high thermal load resistance to PFCs. This article addresses the development of PFCs with emphasis on the integrity of FGLs against thermal loading. The thermal loading test results identified possible combinations and possible bonding techniques for surface materials, FGLs, and metal substrates.