涂层导体用织构复合基带的界面及其扩散行为

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

摘要:

复合基带是一种高强、低磁并较易形成锐利立方织构的高性能织构金属基带，能够较好地满足制备高性能涂层导体用织构基带的要求。采用放电等离子烧结方法制备了Ni5W/Ni12W/Ni5W复合基带并对其内外层界面进行了研究，发现扩散界面有利于外层合金立方织构的形成。同时，将基带在1250 ℃分别经60，120和180 min热处理后，基带外层合金立方织构含量均保持在98%以上。分析表明，在高温热处理阶段复合基带中界面处发生了元素互扩散行为，W元素由芯层扩散至基带表层并在晶界出形成钉扎点，抑制了晶粒的异常长大现象，使复合基带外层合金立方织构在高温热处理阶段具有较好的稳定性。

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.