包晶凝固和高温超导体YBCO的凝固组织(一)  

Peritectic Solidification and Solidification Microstruture of High Temperature Superconductor YBCO(1)

作　　者：朱祖昌[1] 杨弋涛[2] 吴旭炜 王洪 

机构地区：[1]上海工程技术大学,上海201620 [2]上海大学,上海200072 [3]上海市机械制造工艺研究所有限公司,上海200070

出　　处：《热处理技术与装备》2015年第6期85-90,共6页Heat Treatment Technology and Equipment

摘　　要：很多二元合金在冷却凝固中出现包晶凝固。包晶凝固的反应式为:L+α→β。包晶凝固分包晶反应和包晶转变,可以相应表示为:L+α→β和α+B原子→β。包晶凝固组织分常规(非定向)凝固组织和定向凝固组织。呈协同共生或片层状类共晶的定向凝固组织,引起人们很大的兴趣。使高温超导体获得晶界平行于其ab电流传导面和在RE123相基体中引入高稳定细小RE211为强的磁通钉扎中心的组织,能使高温超导体具有优良的性能。十分明显,通过包晶反应进行凝固组织的控制是制备具有高Jc性能的高Tc超导体块材的关键[24]。由此,提出制造高温超导体的设计原则为:1)成分和组织位于相图(Y123+Y211)区;2)保持G/V的数值和V≤Vmax凝固条件使液/固交界面呈平面状;3)增加Vmax以提高生产效率。During cooling procedure many binary alloys exhibit peritectic solidification,i. e. L ＋ α → β.Peritectic solidification can divide into peritectic reaction and peritectic transformation and indicate respectively L ＋ α → β and α ＋ B atoms → β. At present the peritectic solidified microstructure includes normal（ non-unidirectional） and unidirectional microstructure. It is interesting to gain the couple growth microstructure and / or lamellar eutectic-like microstructure for peritectic unidirectional solidified alloys. In order to make the high temperature superconductor having excellent properties,it is very important to allow the Y123 matrix to gain texture structure whose boundaries parallele along current fluid direction on ab plane and introduce high stable dispersed Y211 particales in the Y123 matrix phase as effective pinning centers. Obviously,microstruture control via peritectic reaction is considered to be crucial to fabricate the bulk high Tcsuperconductive materials with high Jcproperty. Hence,the design principles are： 1） put the content and microstructure inside the area of（ Y123 ＋ Y211） of the phase diagram; 2） hold the value of G / V and the condition of V≤Vmaxto make the liquid / solid interface plane shape; 3） increase Vmaxto enhance the production effectiveness.

关 键 词：包晶反应 包晶转变 高温超导体 凝固 显微组织 

分 类 号：TG111.4[金属学及工艺—物理冶金]