约束凝固枝晶尖端扩散场的 Zener 近似因子  

Zener Factor for Diffusion Near Dendrite Tip During Constrained Solidification

作　　者：蔡英文[1] 苏俊义[1] 李建国[2] 傅恒志[2] 

机构地区：[1]西安交通大学 [2]西北工业大学

出　　处：《西安交通大学学报》1998年第10期43-46,共4页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金;中国博士后科学基金

摘　　要：Ｚｅｎｅｒ近似因子是处理约束凝固枝晶尖端扩散场的重要参量．文章从尖端非平衡溶质分配的角度，给出了Ｚｅｎｅｒ近似因子λ的计算公式，指出λ是合金的物理性质及尖端推移速率和界面非平衡效应的综合反映；在此基础上，给出了各种稳态约束枝晶生长模型的适用速率范围，并与实验结果进行了比较．The zener factor, λ, is essential to the diffusion near dendrite tip during constrained solidification. A formula is developed for λ based upon nonequilibrium solidification in which λ is a complex function of alloy properties, tip velocity and interface nonequilibrium effects rather than a constant during the entire range of solidification rate. Determined are the applicable velocity ranges of various models for steady growth of dendrite, the tip radius of which agrees well with experiments.

关 键 词：枝晶尖端 扩散场 Zener近似因子 凝固 合金 

分 类 号：TG111.4[金属学及工艺—物理冶金]