Cu基块体非晶合金板材水平连铸过程的数值模拟  

Numerical simulation on fabrication of Cu-based bulk metallic glasses by horizontal continuous casting

作　　者：蒋博宇[1] 周秉文[1] 王舸 房园 张兴国[1] JIANG Bo-yu;ZHOU Bing-wen;WANG Ge;FANG Yuan;ZHANG Xing-guo(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学材料科学与工程学院,大连116024

出　　处：《中国有色金属学报》2020年第12期2901-2911,共11页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51971049);中央高校基本科研业务费资助项目(DUT19GF110)。

摘　　要：采用ProCast软件研究了(Cu47Zr45Al8)98.5Y1.5块体非晶板材水平连铸过程中的温度场分布和凝固界面变化。结果表明:熔体在中间包内的充型时间为22 s,保温时间不应超过55 s。铸坯的冷却过程分为两个阶段,第一阶段当拉坯速度为1 mm/s时,熔体在石墨内凝壳,冷却速率小于10 K/s,不利于形成块体非晶;第二阶段铸坯的热量直接传递给铜模,冷却速率大于40 K/s。提高拉速及增大过热度有利于凝固界面前移,熔体在液相线温度Tl时的冷却速率大于40 K/s,满足Cu基非晶的临界冷却速率(20 K/s)。改善模具结构,缩短石墨端嵌入模具长度,熔体由Tl冷却至玻璃化转变温度Tg所需的时间减少,有利于获得非晶组织。实验验证发现,拉坯参数为拉坯速度2 mm/s、过热度80 K、石墨嵌入深度20 mm时,可获得具有明亮金属光泽的非晶合金板材。In this paper,the distributions of temperature fields and solidification interface in horizontal continuous casting of(Cu47Zr45Al8)98.5Y1.5 bulk metallic glasses(BMGs)slab were studied by ProCast.The results show that the mold filling time in the tundish is 22 s,and the holding time in the tundish should not exceed 55 s.The slab undergoes two cooling stages.In the first stage,the melt solidifies in the graphite passageway,the drawing speed is 1 mm/s and the cooling rate is less than 10 K/s.In the second stage,the heat of the slab is directly transferred to the copper,and the cooling rate is more than 50 K/s,which is sufficient for the critical cooling rate for CuZr based BMGs(20 K/s).The increase of drawing speed and superheat can promote the solidification interface to move along the casting direction,so that the melt can obtain a large cooling rate above 50 K/s near Tl.By improving the mold structure and shortening the embedding depth of the graphite,the time needed from Tl to Tg is reduced,which is conducive to obtaining amorphous microstructure.The experimental verification reveals that when the daring parameters are drawing speed of 2 mm/s,superheat of 80 K and embedded depth of 20mm,a BMGs slab with shiny metal luster can be obtained.

关 键 词：水平连铸 数值模拟 复合模具 冷却速率 凝固界面 

分 类 号：TG249.7[金属学及工艺—铸造]