“双粉法”制备Bi—2223／Ag带材中CaCuO2最佳含量的确定

采有“双粉法”制备Bi-2223/Ag带材，通过对2212和CaCuO2的不同配比研究，确定了双粉法中CaCuO2的最佳含量，实验结果表明：当前驱粉中CaCuO2相过量5%时，带材的临界电流密度比CaCuO2无过量时高10%左右。这主要是因为在反应过程中，过量的CaCuO2会提供较丰富的液相，促使2212→2223转变过程进行得更彻底。且转变速度提高；但过量值较大（10%～15%)时，过多的液相会导致杂相的偏聚，大尺寸的杂相粒子使其周围的2223相织克构度，晶粒连接性较差，带材的临界电流密度下降。

Optimization of CaCuO2Content in Bi-2223/Ag Tape Made by Two-Powder Process

CaCuO 2 content has been optimized for two powder process. The experimental results indicate that as precursor powders have 5% excessive CaCuO 2, the critical current density of tape increases about 10%. During the reaction process, excessive CaCuO 2 afford enough liquid phase which accelerate the 2223 phase formation, but too much CaCuO 2 (>15%) will produce impure phases at grain boundary. Large impurity particles decrease the texture degree of the 2223 phase and critical current density of the tape.