Interface and Element Diffusion Behavior of the Composite Substrate Used for Coated Conductors

Abstract:

Composite substrate which has high mechanical property and low magnetic property and is easy to form the sharp cube texture in the outer layer can satisfy the requirements of the advanced metallic substrate used for coated conductors. The Ni5W/Ni12W/Ni5W composite substrate has been fabricated by Sparking Plasma Sintering (SPS) followed by traditional cold rolling and recrystallization annealing. The investigation on the interface between the inner layer and the outer layer of the composite substrate shows that the diffusion layer is beneficial for formation of the cube texture in outer layer of the substrate. The fractions of cube texture on the surface of the outer Ni5W layer in the composite substrate all exceed 98%, when the substrate is annealed at 1250 oC for 60, 120 and 180 min respectively. This is possibly caused by element mutual diffusion during the heat-treatment process in the diffusion layer. The grain abnormal growth has been restrained duo to W atom pinning in grain-boundary diffused from inner layer, subsequently stabilizing the cube texture of the outer layer during the severely annealing process.