摘要
本文研究了pb—Sn共晶合金定向凝固条件下电磁搅拌对层片组织的影响。结果发现,Pb—Sn合金共晶组织明显粗化,并且层片间距随着半径的增加而增加。通过引进由流动引起的浓度波动项,利用最小过冷度理论推导出了下式:λ~2V=Ao/(1-A^1Guλ~2/D)。式中Gu=0. 25~μ-0.5~ωl- 5~r,Gu为液固界面前的速度梯度。随半径r增加而增加,这就较好地解释了层片间距λ与r的关系。此外,在试棒的外侧还发现了锡富集层。
Synopsis: Structures of unidirectional solified 38.1% Pb-Sn ertectie alloys with rotarary electromagnetic stirring are studied. It is found that the lamellar spacing of Pb-Sn eutectic increases along the radial direction. This conforms to the the-oretical equation as follows:λ~2v=A_0/(1—A_1Guλ~2/D). where Cu=0.25v^(-0.5_ω^1.5)r. Moreover. a special phenomenon called “eparated cutectic”occurrs in Pb-Sn eutectic.
出处
《铸造技术》
CAS
北大核心
1992年第6期42-44,共3页
Foundry Technology
基金
国家自然科学基金资助项目
关键词
电磁搅拌
PB-SN合金
结构
: Electromangnetic stirring. Pb-Sn alloy structure.
