Effect of back diffusion on overall solidification kinetics of undercooled single-phase solid-solution alloys  

反向扩散效应对过冷单相固溶体合金凝固动力学的影响(英文)

作　　者：王海丰[1] 刘峰[1] 王慷[1] 翟海民[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《Transactions of Nonferrous Metals Society of China》2012年第3期642-646,共5页中国有色金属学报（英文版）

基　　金：Project(2011CB610403) supported by the National Basic Research Program of China;Project(51125002) supported by the National Science Fund for Distinguished Young Scholars of China;Projects(51101122,51071127,50901059) supported by the National Natural Science Foundation of China;Project(111502) supported by the Huo Yingdong Young Teacher Fund,China;Projects(66-QP-2010, 24-TZ-2009) supported by the Free Research Fund of State Key Laboratory of Solidification Processing,China;Projects(JC201008, JC200801) supported by the Fundamental Research Fund of Northwestern Polytechnical University,China;Project(B08040) supported by the Program of Introducing Talents of Discipline to Universities,China

摘　　要：Departing from the volume-averaging method,an overall solidification kinetic model for undercooled single-phase solid-solution alloys was developed to study the effect of back diffusion on the solidification kinetics.Application to rapid solidification of undercooled Ni-15%Cu（mole fraction） alloy shows that back diffusion effect has significant influence on the solidification ending temperature but possesses almost no effect on the volume fraction solidified during recalescence.Inconsistent with the widely accepted viewpoint of Herlach,solidification ends at a temperature between the predictions of Lever rule and Scheil＇s equation,and the exact value is determined by the effect of back diffusion,the initial undercooling and the cooling rate.基于平均体积方法建立过冷单相固溶体合金的凝固动力学模型并研究反向扩散在凝固动力学过程中的作用。模型在过冷Ni-15%Cu(摩尔分数)合金快速凝固中的应用表明:反向扩散显著影响凝固结束温度但对再辉阶段凝固的固相体积分数影响不明显。与Herlach观点相反,凝固结束温度介于杠杆定律和Scheil方程的预测值之间,且其具体值由反向扩散、初始过冷度和冷却速率决定。

关 键 词：Ni-Cu alloy rapid solidification diffusion UNDERCOOLING 

分 类 号：TG111.4[金属学及工艺—物理冶金]