深过冷Ni-31.44%Pb偏晶合金快速凝固行为  

Solidification behavior of highly undercooled Ni-31.44%Pb monotectic alloy melts

作　　者：郑红星[1] 马伟增[1] 季诚昌[1] 郭学锋[2] 杨根仓[3] 李建国[1] 

机构地区：[1]上海交通大学材料科学与工程学院,上海200030 [2]西安理工大学材料科学与工程学院,西安710048 [3]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《中国有色金属学报》2003年第2期339-343,共5页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(50171044);国家杰出青年科学基金资助项目(50125101)

摘　　要：采用熔融玻璃净化和循环过热相结合的方法研究了Ni 31.44%Pb偏晶合金宽过冷区间的凝固组织演化规律;从形核热力学和动力学两方面分析过冷熔体中稳定相(α)和亚稳相(L2)两相的竞争形核规律。研究结果表明:过冷Ni 31.44%Pb偏晶合金在快速凝固阶段本质上是以枝晶方式生长,首先形成α枝晶骨架,再辉重熔后分布于枝晶间的残余液相按照正常凝固模式进行分相/偏晶等后续反应。By using the method of molten glass denucleating combined with superheating cycle, structural evolution of undercooled Ni31.44%Pb monotectic alloy was systematically investigated within the achieved undercooling range from 10 to 286 K. The phase selection of high temperature melts was calculated by adopting steady state and transient state nucleation theories, respectively. The calculation results of nucleation theories show that the undercooled Ni31.44%Pb monotectic alloy melts solidify in the same mode of the undercooled singlephase alloy melts, i.e., undercooled Ni31.44%Pb monotectic alloy solidifies in the form of dendrite essentially during the stage of rapid solidification and after recalescence, the interdendritic residual melts solidify in the equilibrium mode.

关 键 词：偏晶合金 深过冷 NiPb合金 熔融玻璃净化 循环过热 

分 类 号：TG146.15[一般工业技术—材料科学与工程] TG111.4[金属学及工艺—金属材料]