Papers by Author: Z.G. Fan

Abstract: Microstructures and transformation behavior of TiNi shape memory alloy after high temperature ECAE process have been investigated. It is found that the initial coarse grains were refined after high temperature ECAE processes and short annealing at 750°C. Transformation temperatures of TiNi alloy sharply decreased after two ECAE processes, rose obviously when annealed at 750°C for 5min, and quickly rose back after annealing at 500°C for 2 hours. Reasons for phase transformation behavior changes have been discussed.

Abstract: High critical current density Jc under high magnetic field is required in numerous applications for high temperature superconductor YBa2Cu3O7-δ (Y123). Significant efforts have been made to control sample preparation in view of optimized textures and microstructures. In YBa2Cu3O7-δ superconductor, Jc is limited by grain misalignment and by other defaults like secondary phase (Y211), microcracks... So YBaCuO films were prepared by electrophoretic deposition directly on polycrystalline Ag substrate. Melt textured growth (MTG) in low oxygen partial pressure and cold rolling were performed to YBaCuO samples respectively to improve texture growth of the films and to study deformation effect on the texture. The film obtained by melted growth after rolling has better texture orientation than the film without rolling, and presents higher critical current density.